A Systematic Review of Phonological Awareness Interventions for Latino Children in Early and Primary Grades

Abstract

This article summarizes the findings of a systematic review of 15 group and two single-subject experimental design studies that evaluated the effectiveness of phonological awareness interventions for dual language learners (DLL) in preschool through second grade. Studies were evaluated using a Consumer Reports-like rating system. Each study was rated on quality indicators for design characteristics, measurement and reliability, evaluation of treatment effects, and external validity. The effects of phonological awareness interventions for Latino children who are DLL in the early and primary grades are promising, although the studies’ results are tempered by conceptual limitations. Most studies demonstrated acceptable design characteristics and implementation fidelity. Few studies included measures of social validity and consumer satisfaction. Although the review did not identify a single treatment approach to be superior, preliminary evidence suggests that children can benefit from phonological awareness instruction that is explicit and allows for multiple response opportunities. The results of this review also indicate that children who are DLL benefit from bilingual phonological awareness instruction without detracting them from acquiring English phonological awareness skills.

Keywords

dual language learners phonological awareness emergent literacy early childhood

Introduction

Children’s path to reading begins with strong early literacy skills that include phonological awareness or the manipulation and synthesis of spoken words at the word, syllable, and phonemic levels (e.g., rhyming, blending, segmenting, elision; Storch & Whitehurst, 2002). Children’s phonological awareness skills, in conjunction with their alphabet knowledge skills, enable them to apply the alphabetic principle to decode unfamiliar words. Young children with poor phonological awareness skills have difficulty unlocking the alphabetic principle and tend to be struggling readers (Byrne, 2014). Providing these children with effective phonological awareness intervention can reduce their risk of developing persisting academic difficulties (Storch & Whitehurst, 2002).

Many Latino children who are dual language learners (DLL) are at peril of falling behind their peers as only 42% of them enter kindergarten with adequate phonological awareness in Spanish or in English (Fuller, 2011). Reduced phonological awareness, combined with one or more risk factors such as low socioeconomic status, low maternal education, and limited home literacy experiences (National Research Council, 2006), place Latinos in greater jeopardy of becoming struggling readers. Despite substantial evidence that providing young monolingual children with early literacy instruction focusing on phonological awareness reduces their risk of becoming struggling readers (Ehri et al., 2001), research on effective phonological awareness intervention for young Latino children who are DLL is sorely lacking. Nevertheless, teaching phonological awareness skills to Latino children who are DLL during their early and primary grades could improve reading proficiency and academic success for this population.

The purpose of this article is to present a systematic review of the existing literature on phonological awareness interventions for Latino children in the early and primary grades. The primary aims of this systematic review are to summarize and evaluate the effects and quality of existing phonological awareness interventions applied to Latino children who are DLL. The secondary aims of this systematic review are to identify the gaps in the literature, to suggest future research directions, and to provide practitioners with guidelines for delivering effective phonological awareness interventions for Latino children.

Phonological Awareness Instruction for Latino Children Who Are DLL

When evaluating the quality and effects of viable phonological awareness interventions for Latino children who are DLL, an essential question is, “What is the best method for providing phonological awareness instruction to these children?” There is growing evidence that Latino children who are DLL benefit from some of the same phonological awareness instructional strategies as their monolingual peers (Castro, Páez, Dickinson, & Frede, 2011). Both Latino children who are DLL and monolingual children respond well to phonological awareness instruction that is focused and explicit, provides multiple response opportunities, and follows a systematic developmental scope and sequence (Ehri et al., 2001). However, applying these strategies without considering the unique language needs of children who are DLL is insufficient (Castro et al., 2011), as it fails to acknowledge our contemporary understanding of bilingualism. Latino people who are DLL are not simply two monolinguals in one, but rather individuals whose experiences with their two languages impact their learning (Bialystok & Feng, 2011). There is evidence supporting a bidirectional relationship between phonological awareness skills in their two languages, with children who have high phonological awareness skills in their first language also exhibiting high phonological awareness skills in their second language (Anthony et al., 2011). There also is evidence that the nature of a language influences the ease of phonological awareness tasks (Pollard-Durodola & Simmons, 2009). Because children who are DLL experience two languages, it is important to be cognizant of the differences between their two languages, and the potential influence that this difference plays in their phonological awareness acquisition. Adequate phonological awareness instruction for Latino children, therefore, needs to consider the following: (a) the relation between children’s phonological awareness skills across their two languages, (b) the similarities and differences between English and Spanish phonological awareness acquisition, and (c) how to best assess dual phonological awareness skills in Latino children to measure the effects of intervention.

Interlanguage relations of phonological awareness skills

Latino children’s Spanish and English phonological awareness skills are highly interrelated; those with high Spanish phonological awareness skills are also likely to exhibit high English phonological awareness skills (Dickinson, McCabe, Clark-Chiarelli, & Wolf, 2004; Durgunoğlu, Nagy, & Hancin-Bhatt, 1993; López & Greenfield, 2004). This theoretical finding is supported by growing evidence that Latino children who are DLL receiving bilingual phonological awareness interventions make gains in both their Spanish and English phonological awareness skills (Durán, Roseth, & Hoffman, 2010). However, children who are DLL and receive phonological awareness interventions in English make gains in English phonological awareness skills, but many fail to catch up to their monolingual peers (Castro et al., 2011). Providing young Latino children who are DLL with phonological awareness interventions that support their acquisition of phonological awareness skills in their two languages has the benefit of promoting their biliteracy and bilingual skills, as well as improving their employment and social opportunities as they transition to adulthood (Bialystok & Feng, 2011).

Differences and similarities of English and Spanish phonological awareness

Delivering interventions for Latino children who are DLL that support their acquisition of phonological awareness in both languages requires an understanding of the linguistic differences between English and Spanish (Pollard-Durodola & Simmons, 2009). Directly translating phonological awareness curricula from English to Spanish without considering the differences between the languages reduces the adequacy of phonological awareness instruction (Peña, Bedore, & Kester, 2016). English contains many monosyllabic, consonant-vowel-consonant (CVC) words (e.g., cat, mop, rat). In contrast, Spanish contains primarily three- to four-syllable words, consonant-vowel-consonant-vowel (CVCV) words, and few final consonants (e.g., l, d, n, s, r) (Jiménez González & García, 1995). These language differences affect the ease of a phonological awareness task in each language (Anthony et al., 2011; Gorman & Gillam, 2003). In English, the manipulation of words at the sound level is vital for reading, but in Spanish, blending and segmenting words at the syllable level are most predictive of future reading (Pollard-Durodola & Simmons, 2009). Although the typical sequence of phonological awareness development in English begins with larger speech segments (e.g., sentences, compound words) and progresses to smaller speech segments (e.g., words, syllables, phonemes), the developmental progression is different in Spanish (Gorman & Gillam, 2003). In Spanish, two-syllable words are easier to manipulate than three- to four-syllable words, and compound words are the most difficult to manipulate (Anthony et al., 2011).

Phonological awareness assessment and approaches to instruction

Strong phonological awareness interventions are contingent upon assessments that accurately capture the effects of these interventions on Latino children’s development of early literacy. Shortcomings in the assessments result in an obscured understanding of the effects of the phonological awareness intervention. Peña and colleagues (2016) warn against translating assessments directly from English to Spanish, as this reduces their validity. For example, an English phonological awareness assessment containing mostly monosyllabic, CVC words is inappropriate in Spanish. Thus, differences in the complexity of phonological awareness tasks in English and Spanish must be considered when constructing assessments to evaluate treatment effects validly.

Despite theories recommending the best approach of phonological awareness interventions for Latino children who are DLL, there is no empirically proven gold standard for this population. Hence, our understanding of effective phonological awareness interventions for Latino children in preschool through second grade is limited. Because phonological awareness is foundational to reading fluently, and children up to second grade are still acquiring the decoding skills to read texts, it is important to identify efficacious phonological awareness interventions for these children. A systematic review of phonological awareness interventions is needed to provide insight into the effects and quality of interventions available for children who are DLL, to provide practitioners with guidelines for phonological awareness interventions, and to guide future research.

A Systematic Review of Phonological Awareness Interventions for Latino Children

Systematic reviews allow for an exhaustive summary of the current body of phonological awareness interventions by evaluating the quality and efficacy of studies based on their design characteristics and intervention effects. A systematic review will help guide teachers and clinicians in selecting appropriate interventions for young Latino children who are DLL, and identify areas needing further research. This review extends previous reviews by including younger children (i.e., preschoolers) and by analyzing studies that have specifically evaluated the effects of phonological awareness interventions. Many of the previous systematic reviews only evaluated the findings of group design studies using effect sizes (Buysse, Peisner-Feinberg, Páez, Hammer, & Knowles, 2014). This review extends this body of literature by augmenting effect sizes with ratings of quality indicators, such as research design, measurement, and external validity. This review also expands upon previous reviews by including single-subject designs.

The following research questions were addressed:

Research Question 1: How are the experimental studies of DLL phonological awareness interventions for children in preschool through second grade distributed in terms of type of intervention, language of instruction, and grade level?

Research Question 2: What is the overall quality of studies evaluating phonological awareness interventions for Latino children who are DLL in preschool through second grade?

Research Question 3: What are the effects of phonological awareness interventions for Latino children who are DLL in preschool through second grade when categorized by type of intervention and language of instruction?

Method

Selection of Research Articles

The literature search included studies published in peer-reviewed journals from 2000 to 2017 as this reflects the surge of research focusing on Latino populations in the last two decades. Studies included in this review met the following criteria: (a) they evaluated the effects of a phonological awareness intervention, (b) they had a phonological awareness outcome measure, (c) they targeted interventions for Latino children who are DLL in preschool through second grade, (d) they separated children who are DLL from the other participants in the study, and (e) they did not include children with identified disabilities (because we still do not have enough information regarding the typical development of Spanish and English phonological awareness skills in young Latino children who are DLL).

Studies were found using the Education Resource Information Center (ERIC), PsychInfo, and Google Scholar online databases using keywords: dual language learners, or English language learners, or bilinguals, or Spanish-English, as well as one or more of the following terms: phonological awareness, phonemic awareness, early literacy, emergent literacy, or reading interventions. These search terms represent ways research journals describe interventions related to phonological awareness. In total, 13 published studies met the criteria. We also searched for specific authors and journals that routinely publish research related to DLL literacy interventions, resulting in four more articles.

Research articles were selected from scholarly journals that applied a peer review process and were reputable in disseminating research related to early reading skills. These journals varied in their target audiences, including ones targeting general and special educators, speech–language pathologists, and psychologists. Searching for studies meeting the inclusion criteria across disciplines was important as these types of professionals are the ones most likely to deliver phonological awareness instruction to Latino children who are DLL. Studies were searched in a variety of journals, including Early Childhood Research Quarterly, Journal of Educational Psychology, Learning Disability Quarterly, Child Development, Journal of School Psychology, and Exceptional Children.

We first grouped articles by design, and evaluated 15 group design studies and two single-subject design studies. For each design, articles were divided by language of instruction: English-only, home language, or both languages. Studies were further divided into one of three types of phonological awareness instruction. phonological awareness + alphabet instruction included studies that combined phonological awareness instruction with teaching of alphabet letters and sounds. Phonological awareness-only instruction included interventions that focused only on teaching distinct phonological awareness skills. Curriculum-based instruction included interventions that taught phonological awareness skill in the context of other oral language and emergent literacy skills such as comprehension, vocabulary, and writing.

Criteria Rating System

This systematic review was completed using a framework for evaluating the effects and quality of interventions developed by Goldstein, Lackey, and Schneider (2014) that utilizes a set of quality indicators that are largely parallel across group and single-subject experimental designs. This framework has been used to review existing research on social skills interventions for children with Autism spectrum disorders (Goldstein et al., 2014). Individual studies were rated across four categories, as shown in Tables 1 and 2: (a) study design and internal validity (e.g, design, group equivalence; Gersten et al., 2005; Horner et al., 2005; Kratochwill et al., 2012; What Works Clearinghouse, 2018), (b) measurement features (e.g., reliability, implementation fidelity; Gersten et al., 2005; Horner et al., 2005), (c) results (e.g., effect sizes, statistical analysis, visual analysis; Kratochwill et al., 2012), and (d) external validity (e.g., setting, social validity, consumer satisfaction; Kratochwill et al., 2012). These four categories were selected because they have been well-documented as constituting quality indicators for group design (Gersten et al., 2005; What Works Clearinghouse, 2018) and single-subject experimental design studies (Horner et al., 2005; Kratochwill et al., 2012). Operational definitions for each quality indicator are presented in Tables 1 and 2. In total, 14 quality indicators were used for single-subject designs, and 15 quality indicators were used for group design studies. For both designs, a numeric rating was assigned to each quality indicator: 1 = unacceptable, 2 = minimal, 3 = acceptable, and 4 = exemplary.

Table 1.

Design and Measurement Quality Indicators for Group and Single-Subject Design Experiments.

Design characteristics and internal validity			Criteria	Measurement features
Criteria	Group studies	Single-subject design studies	Criteria	Both group studies and single-subject design studies
Design	1. Lack of randomized design. 2. Lack of randomized design with a large sample or randomized with a small sample. 3. Randomized design with sufficiently large sample size from a specified population. 4. Randomized design with large sample size and counterbalancing of change agents.	Experimental design set up as follows: 1. Pre-experimental design (e.g., AB or ABAC design without counterbalancing). 2. Fewer than three replications across participants. 3. At least three replications across participants. 4. At least three replications demonstrated within and replicated across at least three participants.	Measurement	1. Poor measurement scheme or definitions; or reliance solely on verbal report rather than objective measures. 2. Clear, replicable, and precise operational definitions. 3. Valid measure with clear, replicable, and precise operational definitions, with either multi-method, multisource, or blind coding. 4. Multi-method (at least two measurements used to assess the primary outcomes); multisource (sampling outcomes from two different sources, e.g., parents, teachers); blind coders; good validity.
Group equivalence	1. No demonstration of group equivalence. 2. No random assignment, with post hoc test to determine group equivalence. 3. Random assignment. 4. Matching and randomization with post hoc tests to determine group equivalence.		Reliability	1. No mention of reliability or poor or questionable reliability for measures.2. Observational measure is inconsistent or has marginal interobserver agreement scores. Tests or instruments rely on test manual with no reliability estimates for the study sample.3. Observational measure demonstrates high interobserver agreement. Tests or instruments have adequate reliability estimates for the study sample.4. Observational measure provides sufficient detail to rule out effects of chance agreement and a breakdown is provided for each response category. High reliability estimates for the study sample for tests or instruments.
Comparison group	1. No control group.2. Active control group is employed.3. Viable alternate treatment serves as a comparison within a RCT.4. Empirically supported alternative treatment serves as a control group within a RCT.		Implementation fidelity	1. Replication would not be possible based on the description of the treatment.2. Includes good operational definitions of the treatment.3. Evidence of implementation fidelity is provided as well as good operational definitions of treatment.4. Good operational definitions of treatment are provided, procedural reliability checks are reported, and there is a manual or formal training used to reach established mastery criterion.
Attrition	1. No mention of attrition although it’s clearly a threat to internal validity.2. Attrition noted as a limitation and threat to internal validity.3. Statistical analysis used to determine attrition did not impact the study.4. No or low attrition is reported.

Note. 1 = unacceptable; 2 = minimal; 3 = acceptable; 4 = exemplary; RCT = randomized control trial.

Table 2.

Characteristics and External Validity Quality Indicators for Group and Single-Subject Design Experiments.

General characteristics and design			External validity
Criteria	Both group studies and single-subject design studies		Criteria	Both group studies and single-subject design studies
Rationale	1. Rationale for study is not clear or seems unimportant.2. Minimal empirical or theoretical context.3. Clear and thorough literature review provides strong rationale, with either theoretical or empirical evidence.4. Theoretical and empirical evidence indicates high importance.		Site for implementation	1. No attempt to relate findings to real world.2. Laboratory, clinical, or segregated setting, but sufficient description to judge degree of generalizability.3. Simulated or somewhat contrived environment.4. High external validity with respect to everyday contexts and environments.
Robust treatment effects	1. Treatment effects lacking or questionable.2. Weak effects for key outcomes.3. Strong treatment effects for key outcomes.4. Strong treatment effects with sufficient details for primary and secondary outcomes.		Participant selection	1. Unable to identify participants.2. Meager description of participant characteristics.3. Sufficient description of participant characteristics and selection criteria to allow replication.4. Excellent description with high degree of generalizability.
Maintenance and generalization	1. No acknowledgment of generalization/maintenance.2. Report some, but not impressive results of maintenance and/or generalization.3. Meets criteria for generalization or maintenance; or some generalization/short-term maintenance.4. Analysis of generalizations and maintenance reported; durable effects across people, settings, tasks, and such.		Consumer satisfaction with the treatment	1. No mention of consumers’ satisfaction with the treatment or outcomes.2. Some mention of consumers’ satisfaction or willingness to continue the treatment.3. Some systematic assessment of consumer’s satisfaction4. Objective assessment of consumer’s satisfaction.
	Group design studies	Single-subject design study
Statistical treatment	1. Inappropriate statistical analysis; sample small; high likelihood of Type 1 error.2. Appropriate unit of analysis; contains sufficient detail to calculate effect sizes, power, and potential for Type 1 error.3. Meets first two from above and reports effect sizes.4. Appropriate unit of analysis; control of family-wise error; large sample; effect sizes and confidence intervals reported.	1. No effect size reported.2. Effect size based on pre–post scores.3. Report and interpret effect sizes for primary outcomes.4. Report large effect sizes with appropriate analysis.
Quality of baseline		When multiple plots or figures, most show the following:1. Fewer than three data points or one or none of criteria met.2. High-quality baseline for two of four criteria above.3. High-quality baseline for three of four criteria above.4. Meets four criteria: length of baseline appropriate; stable baseline; level warrants treatment; trend not in undesirable direction.
Visual analysis of treatment effects		1. No reliable change in behavior demonstrated.2. Same, for at least half of the replications.3. Same as above, for most of the replications (e.g., three of four).4. Outcomes: (a) Large change in level of behavior; (b) minimal overlap with baseline or clear trend in desired direction; (c) adequate length and stable data within and across conditions, replicated across all participants.

Note. 1 = unacceptable; 2 = minimal; 3 = acceptable; 4 = exemplary.

Data Analysis

For each study, an average across the quality indicators was calculated (see Tables 3 and 4). An overall average of ratings also was calculated across intervention types to facilitate comparisons (e.g., all studies that used Phonological Awareness only instruction). Circles ranging from white to black were used to graphically represent scores for each criterion. White or partially white circles represent high ratings (i.e., white = exemplary, and partially white = acceptable) while low ratings are indicated by partially black (minimal) or black circles (unacceptable).

Table 3.

Evaluation of Group Design Studies.

Citations	Average rating	Design characteristics and internal validity				Measurement and reliability features			Evaluation of treatment effects				Dimensions of external validity				Effect sizes
Citations	Average rating	Design	Group equivalence	Comparison group	Attrition	Measurement	Reliability	Implementation fidelity	Rationale	Robust treatment effects	Statistics	Maintenance and generalization	Implementation site	Participant selection	Consumer satisfaction	Social validity	Effect sizes
English
PA + Alphabet instruction
Roberts and Neal (2004; Preschool)	2.53	◔	◔	◔	○	◔	◔	◔	◔	◕	•	•	◔	◔	•	◕	0.15
Solari and Gerber (2008; kindergarten)	2.80	◔	○	◔	○	◔	◕	◕	◔	○	◔	◕	◔	◔	•	◕	–1.21 to 0.071
Calhoon, Al Otaiba, Cihak, King, and Avalos (2006) (first)	2.40	◕	◕	◕	•	◕	◕	○	◔	◔	•	•	○	◔	○	◕	1.11
Average rating by indicator	2.58	2.67	3.00	2.67	3.00	2.67	2.33	3.00	3.00	3.00	1.67	1.33	3.33	3.00	2.00	2.00
PA only
Leafstedt, Richards, and Gerber (2004; Kindergarten)	2.40	•	•	◕	○	◔	•	◕	◔	○	◔	◕	◔	○	•	◕	0.55 to 2.27
Average rating by indicator	2.40	1.00	1.00	2.00	4.00	3.00	1.00	2.00	3.00	4.00	3.00	2.00	3.00	4.00	1.00	2.00
Curriculum based
Han, Vukelich, Buell, and Meacham (2014; Preschool-second)	2.33	•	•	•	◔	◔	•	◕	◔	○	◔	○	○	◕	•	◕	0.47 to 0.59
Vaughn, Cirino, et al. (2006; first)	2.87	◔	◔	◕	○	◔	◕	○	○	◔	◔	◕	◔	○	•	◕	English: 1.01/Spanish: .76
Linan-Thompson, Vaughn, Hickman-Davis, and Kouzekanani (2003; second)	2.53	•	•	•	○	○	•	○	○	◔	◕	◔	◔	○	•	◕	0.48 to 0.52
Average rating by indicator	2.58	1.67	1.67	1.33	3.67	3.33	1.33	3.33	3.67	3.33	2.67	3.00	3.33	3.33	1.00	2.00
Citations	Average rating	Design characteristics and internal validity				Measurement and reliability features			Evaluation of treatment effects				Dimensions of external validity				Effect sizes
Citations	Average rating	Design	Group equivalence	Comparison group	Attrition	Measurement	Reliability	Implementation fidelity	Rationale	Robust treatment effects	Statistics	Maintenance and generalization	Implementation site	Participant selection	Consumer satisfaction	Social validity	Effect sizes
Both languages
																	English	Spanish
PA + Alphabet instruction
Quiroga, Lemos-Britton, Mostafapour, Abbott, and Berninger (2002; first)	2.00	•	•	•	○	◔	•	◕	○	◔	•	•	◔	◕	•	◕	Unable to calculate
Average rating by indicator	2.00	1.00	1.00	1.00	4.00	3.00	1.00	2.00	4.00	3.00	1.00	1.00	3.00	2.00	1.00	2.00
PA only
Gerber et al. (2004; Kindergarten-first)	2.33	◕	•	◕	•	◔	◕	◔	○	◕	◕	◔	◔	◔	•	◔	0.11 to 2.16	0.046 to 0.58
Average rating by indicator	2.33	2.00	1.00	2.00	1.00	3.00	2.00	3.00	4.00	2.00	2.00	3.00	3.00	3.00	1.00	3.00
Curriculum based
Barnett, Yarosz, Thomas, Jung, and Blanco (2007; Preschool)	2.64	◔	◔	◕	○	◔	◕	NA	◔	◔	◔	•	○	◔	•	◕	R² = .24 to .39	R² = .27 to .33
Farver, Lonigan, and Eppe (2009; Preschool)	3.07	○	◔	◔	○	◔	○	◔	◔	○	◔	•	◔	○	•	◔	0.02 to 0.63	0.47 to 0.83
Calhoon et al. (2007; first)	2.40	◕	◕	◕	•	◕	◕	○	◔	◔	•	•	○	◔	○	◕	−0.19	NA
Vaughn, Linan-Thompson et al. (2006; first)	2.60	◔	◔	◔	◕	◔	◕	○	◔	◔	◔	•	◔	◔	•	◕	0.07	0.73
Average rating by indicator	2.85	3.50	3.00	2.50	4.00	3.00	3.00	3.00	3.00	3.50	3.00	1.00	3.50	3.50	1.00	2.50
Spanish
PA + Alphabet instruction
Linan-Thompson, Bryant, Dickson, and Kouzekanani (2005; Kindergarten)	2.20	•	•	◕	○	◕	•	○	◔	◔	◕	•	○	◕	•	◕	NA	−0.21 to 0.52
Average rating by indicator	2.20	1.00	1.00	2.00	4.00	2.00	1.00	4.00	3.00	3.00	2.00	1.00	4.00	2.00	1.00	2.00
Curriculum based
Vaughn, Mathes, et al. (2006; first)	2.93	◔	○	◕	○	◔	◕	○	○	○	◔	•	◔	○	•	◕	0.54	0.81
Average rating by indicator	2.93	3.00	4.00	2.00	4.00	3.00	2.00	4.00	4.00	4.00	3.00	1.00	3.00	4.00	1.00	2.00
Exemplary				Acceptable					Minimal						Unacceptable
○				◔					◕						•

Note. PA = phonological awareness.

Table 4.

Evaluation of the Single-Subject Design Studies.

Citations	Average rating	Design characteristics and internal validity				Evaluation of treatment effects						Dimensions of external validity				Effect sizes
Citations	Average rating	Design	Measurement	Reliability	Implementation fidelity	Rationale	Robust treatment effects	Quality of baseline	Visual analysis	Statistics	Maintenance and generalization	Implementation site	Participant selection	Consumer satisfaction	Social validity	Effect sizes
English
PA + Alphabet instruction
Gyovai, Cartledge, Kourea, Yurick, and Gibson (2009; Kindergarten-first)	2.79	○	◔	◔	○	○	◔	○	◔	•	•	◔	◔	•	◕	Tau-U: 52%
Average rating by indicator	2.79	4.00	3.00	3.00	4.00	4.00	3.00	4.00	3.00	1.00	1.00	3.00	3.00	1.00	2.00
PA only
Healy, Vanderwood, and Edelston (2005; first)	1.86	•	◑	◑	•	○	○	•	•	◑	•	○	○	•	◑	Unable to calculate
Average rating by indicator	1.86	1.00	2.00	2.00	1.00	3.00	3.00	1.00	1.00	2.00	1.00	3.00	3.00	1.00	2.00
Exemplary				Acceptable				Minimal				Unacceptable
○				◔				◕				•

Note. PA = phonological awareness.

The authors, certified speech–language pathologists with experience conducting both group and single-subject design studies, evaluated the studies. Prior to conducting the current systematic review, they were trained on how to use the evaluation framework that is used in this study. They also completed a previous systematic review on another topic. The authors initially rated studies concurrently until their inter-rater reliability was 80% or higher. When they disagreed on one of the ratings, they discussed it with the third author until an agreement was made. For the current study, 20% of the studies were randomly selected to calculate inter-rater reliability using Cohen’s kappa (Cohen, 1992), which controls for chance agreement. Inter-rater reliability was very high (i.e., Cohen’s kappa = 0.904).

Dependent Variables and Effect Sizes

The dependent variables used to measure children’s gains in their phonological awareness skills varied across studies. English phonological awareness outcome measures included children’s gains on the Dynamic Indicators of Basic Early Literacy Skills (DIBELS; Kaminski, Smith, & Laimon, 2002), Individual Growth and Developmental Indicators (IGDIs; McConnell, Bradfield, Wackerle-Hollman, & Rodriguez, 2012), and the Word Identification and Word Attack subtests from the Woodcock-Johnson Test of Achievement (WJTA; Woodcock, McGrew, & Mather, 2001). Studies that evaluated Spanish phonological awareness outcomes also included assessments such as the Spanish version of the Comprehensive Test of Phonological Processing-2 (CTOPP-2; Wagner, Torgesen, Rashotte, & Pearson, 2013) and the Spanish version of the DIBELS, the Indicadores Dinámicos del Éxito en La Lectura (IDEL; Baker, Cummings, Good, & Smolkowski, 2007).

Effect sizes were calculated for both the group and single-subject design studies when the reported data permitted their calculation. Effect sizes for the group designs were calculated using Cohen’s (1992) d. A Cohen’s d of .20 is considered a small effect, .50 a medium effect, and .80 a large effect. For the single-subject design studies, effect sizes were calculated using Tau-U (Parker, Vannest, Davis, & Sauber, 2011). Tau-U calculates the percentage of non-overlap between the phases and the percentage of data showing improvement between the phases. The benefit of using Tau-U over other traditional non-overlap effect size methods (e.g., percentage of non-overlap data) is that Tau-U accounts for trend in the baseline. Tau-U is also flexible, allowing for a calculation of effects for each baseline-intervention pair and for a calculation of the average of all Tau-U scores. Tau-U yields scores ranging from 0% to 100% (Rakap, 2015). A score of 65% or less is considered ineffective or questionable, a score between 66% and 92% is considered effective, and a score equal to or greater than 93% is considered very effective. The Tau-U effect sizes were computed using a software application developed by Vannest and colleagues (Vannest, Parker, Gonen, & Adiguzel, 2016).

Results

Distribution of Studies

When looking at interventions by type of instruction, eight were Curriculum-Based, six combined Phonological Awareness + Alphabet Instruction, and three were Phonological Awareness-Only. Nine of 17 were delivered only in English, six in both languages, and two in Spanish. Of the English studies, four combined Phonological Awareness + Alphabet Instruction (three group and one single-subject design), two were Phonological Awareness-Only, and three were Curriculum-Based. Studies conducted in both languages included one that combined Phonological Awareness + Alphabet Instruction, one that was Phonological Awareness Only, and four Curriculum-Based interventions. Spanish language interventions consisted of one combined Phonological Awareness + Alphabet Instruction and one Curriculum-Based study.

Four studies focused on children in preschool, five targeted children in kindergarten, seven studies included children in first grade, and one study focused on second grade. Most interventions were delivered in small groups by teachers or paraprofessionals (Table 5). Interventions ranged from 6 weeks to a full-school year. The dosage of the interventions ranged from 15 to 50 min per session.

Table 5.

Description of Studies Systematic Reviews.

Authors	Grade	Classroom context	PA skill(s) targeted	Format/setting	Sample size	Intervention	Instructional approach	Interventionist	Dosage	PA outcomes	Results
English
PA + Alphabet instruction
Roberts and Neal (2004)	preschool	Not specified	Rhyming	Small group	11	Group A: Letter knowledge and rhyming.Group B: Comprehension	Rhyming taught by asking children to identify which word rhymed with the target word out of a field of two. In total, 10 CVC words presented in each session. Letters taught by asking children to name letters. One letter was presented per session.	Undergraduate assistants and classroom teachers.	20 to 25min sessions; 3x/week/16-week total	Research-developed assessment of rhyming (identification task)	Neither group made gains in PA
Solari and Gerber (2008)	kinder	Not specified	Onset, rime, blending, and segmentation	Small group	82	Intensive PA intervention with alphabet knowledge vs. combined PA + Listening Comprehension vs. brief PA intervention control group	Targeted PA and alphabet instruction	Graduate students	20 min sessions; 3x/week	(a) Rime detection; (b) onset detection; (c) segmentation; (d) CTOPP; (e) Story Recall, Word ID, and Word Attack subtests from WJTA-III; (f) PPVT	Group receiving Listening Comprehension + brief PA instruction outperformed the PA intensive group and control group on almost every measure.
Calhoon, Al Oitaba, Greenberg, King, and Avalos (2006)	first grade	Two-way bilingual immersion	Segmentation	Whole group and small groups	78	Peer-Assisted Learning Strategies (PALS)	Dyad of high performing students mentor lower performing students. PA and alphabet skills taught by: (a) saying the letter names and sounds; (b) segmenting CVC words; (c) decoding CVC words; (d) reading simple stories with the targeted decodable words and sight words.	Teachers and peers	30-35 min sessions; 3x/week; 20 weeks total	PSF, NWF, and ORF subtests from DIBELS	DLL children in in the PALS condition demonstrated larger gains on the PSF and NWF. The control group did better on the ORF measure.
Gyovai, Cartledge, Kourea, Yurick, and Gibson (2009)	kinder-first grade	English-immersion classroom	Initial sound identification	Small groups;smallroomadjacent to classroom	12	Early Reading Intervention (Connected sounds of words and spelling)	Used model-lead-test approach: (a) introduce letter and sound; (b) isolate initial sound; (c) reintroduce target sound; (d) practice phonological and spelling skills	Graduate students	20 min sessions; 2 to 4x/week; 7 to 15 weeks total	(a) PSF from the DIBELS; (b) Letter Word Id. and Word Attack WJTA-III; (c) Curriculum-based measures of PA skills	In total, five out of the 12 students improved status to benchmark, two remained in benchmark, and one regressed from strategic to intensive. Positive effect on phoneme segmentation skills.
PA only
Healy, Vanderwood, and Edelston (2005)	first grade	Not specified	Not specified	Small groups	15	Sounds and Letters for Readers and Spelllers	Not specified	Graduate students	30 min sessions; 2x/week; ~16 weeks total	PSF subtest from DIBELS	Children improved PA skills as indicated with large effects.
Leafstedt, Richards, and Gerber (2004)	kinder	Not specified	Early PA skills (rime and onset identification) and late PA skills (segmenting of sounds)	Small groups. Children grouped into high, medium, and low performing groups.	46	Early Reading Project	Used Core Intervention model that applied a corrective staircase, contingent feedback, reteaching.	Special education teachers	15 min sessions; 2x/week; 10 weeks total; 300 min total	Research-developed measures of PA (onset-rime identification, phoneme segmentation; Word Attack subtest from WJT-III; NSF and PSF from DIBELS; PPVT	The high and medium groups outperformed the control group but there were no differences between the low performing group and the control group.
Curriculum based
Han, Vukelich, Buell, and Meacham (2014)	Preschool-second grade	Not specified	Not specified	Small group	102	Creative Curriculum	Not specified	Teachers	One 10 min PA and alphabet knowledge session per day. Low performing children received 30 min of tutoring twice per week.	Rhyming and Alliteration subtests from the IGDIs	Children who were DLL made gains over time in their rhyming and alliteration skills. By second grade, there was not a difference in performance between monolingual and DLL children.
Vaughn, Cirino, et al. (2006)	first grade	Not specified	Phoneme discrimination and phoneme blending and segmenting	Small groups of three to five children	48	Beginning English reading curriculum modified for DLLs by including language-support activities	Direct instruction including phonemic awareness instruction. Children required to isolate initial, medial, and final sounds. Also included blending and segmenting. Teacher-modeled tasks and provided feedback.	Bilingual research assistants	50 min per day; 5 days/week; 7 months total	(a) English/Spanishassessments; (b) Letter Naming; (c) CTOPP; (d) TOPPS-S; (e) DIBELS; (f) IDEL	Children in the treatment group did better than the control in their English and Spanish PA skills than the control group. No improvement on the DIBELS/IDEL measures, however.
Linan-Thompson, Vaughn, Hickman- Davis, and Kouzekani (2003)	second grade	Early-transition program	Phoneme segmentation, blending, deletion, manipulation	Individual/small groups	26	Latters to Literacy and Phonemic Awareness in Young Children: A Classsroom Curriuculum	Instruction modified for DLLs by providing pictures and completing auditory discrimination tasks. Intervention involved phonological awareness, level reading, word study, and writing.	Teachers	30 minute sessions; 5x/week; 13 weeks total	(a) Word Attack and Passage Comprehension subtests from W-MLS; (b) PSF from DIBELS; (c) Test of Reading Fluency	Children only made gains on phoneme segmentation fluency and passage comprehension.

Both languages
PA + Alphabet instruction
Quiroga, Lemos-Britton, Mostafapour, Abbott, and Berninger (2002)	first grade	English-immersion classroom	Syllable and phoneme segmentation	Individual sessions	8	(a) Spanish and English PA training program (syllable segmentation, phoneme segmentation); (b) Alphabetic training in spelling-phoneme correspondence using Talking Letters Program	Spanish: Played “Sounds Games” (a) Detecting a target sound out of field of words; (b) detecting if a sound was missing in the medial position; (c) omitting sounds in words; (d) sound substitutions in words. English: Counted number of syllables and phonemes in words using counters.	Bilingual psychologists	30 min sessions; 2x/week; 6 weeks total	Word Identification and Word Attack subtests from WJTA-III	Children who were DLL who received the intervention raised their English reading scores by a standard deviation of 0.8 for real words, and by 0.5 standard deviations on non-words.
PA only
Gerber et al. (2004)	kinder-first grade	Not specified	Onset-rime detection in kindergarten, and phoneme segmentation, and blending first grade	Not specified	142	Core Intervention Model	Used Cored Intervention model that applied a correction staircase, contingent feedback, and reteaching.	Undergraduate bilingual tutor	30 min sessions; 10 sessions total	(a) Spanish/English research-developed measures of early developing PA onset/rime and (b) Late developing PA; segmentation	Children in intervention improved Spanish PA skills and English segmenting skills, but did not make gains on English onset/rime identification.
Curriculum based
Barnett, Yarosz, Thomas, Jung, and Blanco (2007)	preschool	Some students in English-immersion, other in Two-Way bilingual classrooms	Rhyming, phoneme deletion	Whole group; classroom	150	High Scope Curriculum	Not specific	Classroom teachers	School year (no further details provided)	Spanish/English research-developed measure of PA including: phoneme deletion, rhyme recognition, and alphabet recognition	Children receiving bilingual instruction made gains in both languages than children in English-immersion classroom.
Farver, Lonigan, and Eppe (2009)	preschool	Some children in English-immersion classrooms, others in transitional bilingual classrooms	Word and syllable blending, elision	Small groups; small room to adjacent classroom	96	Group A: English-only High Scope with Literacy Express; Group B: transitional instruction through parallel Spanish-English High Scope + Literacy Express; Group C: English, High Scope only (control)	Utilized word games that used picture-puzzles and other manipulatives to manipulate words. Word manipulations were developmentally sequenced.	Bilingual graduate assistants	20 min lessons; 4x/week; 21 weeks total	Spanish/English Pre-CTOPP	Children in the English and transitional treatment groups did better than control group. Only children receiving bilingual instruction made gains on Spanish PA.
Calhoon, Al Otaiba, Cihak, King, and Avalos (2007)	first grade	Two-way bilingual immersion program	Segmentation	Small groups	76	Peer-Assisted Learning Strategies	PA and alphabet skills taught by: (a) saying the letter names and sounds; (b) segmenting CVC words; (c) decoding CVC words; (d) reading simple stories with the targeted decodable words and sight words. Also worked on story sharing skills, including making predictions about stories.	Classroom teachers	30-35 min sessions; 3x/week; 20 weeks total	LNF, PSF, NWF, and subtests from DIBELS	DLL children in PALS condition outperformed children in control condition on the PSF, NWF, and LNF tasks.
Vaughn, Linan-Thompson et al. (2006)	first grade	Spanish study: conducted in TransitionalBilingual Classrooms. English study:conducted in English-immersion classrooms	Phoneme identification and phonemesegmentation and blending	Small group of three to five students	Spanish study: 94; English study: 96	English study: Proactive Reading, adapted for children who were DLL by using visuals, gestures, and clarifications. Spanish study:Lectura Proactiva	Direct Instruction. Children taught to segment words into phonemes and blend phonemes back into words.	Hired bilingual researchers	50 min sessions; 5x/week; ~8 months total	(a) Letter Naming; (b) CTOPP; (c) TOPP-S; (d) DIBELS; (e) IDEL	Spanish study: children in intervention group made large gains on their Spanish PA skills. English study: children in the intervention made moderate gains on their Spanish PA skills.
Spanish
PA + Alphabet instruction
Linan-Thompson, Bryant, Dickson, and Kouzekanani (2005)	kinder	Not specified	Segmenting and blending of phonemes	Small groups	128	Systematic explicit Spanish reading instruction	Direct instruction. Modeling/leadgroup responses, where children blended and segmented phonemes using manipulatives that were gradually faded.	Classroom teachers	20 min sessions; 3x/week; ~12 sessions total	Tejas Lee	Children in the experimental group caught up to their typically developing peers on syllable blending and syllable identification; however, they continued lagging behind their peers on phoneme blending and phoneme deletion.
Curriculum based
Vaughn, Mathes, et al. (2006)	first grade	Transitional bilingual classrooms	Segmenting and blending at the phoneme level	Small groups of three to five children	69	Letura Proactiva	Direct instruction. Instruction included modeling, increased practice opportunities, guided and independent practice.	Bilingual certified teachers	50 min sessions; 5x/week; ~7 months total	(a) CTOPP; (b) TOPP-S	Children in the intervention group made large gains on their Spanish PA skills, but there was no difference in children’s English PA skills between the treatment and control groups.

Note. PA = phonological awareness; CVC = consonant-vowel-consonant; PSF = Phoneme Segmentation Fluency; ORF=oral reading fluency; LNF=Letter Naming Fluency; NWF=Nonword Fluency; DIBELS = Dynamic Indicators of Basic Early Literacy Skills; WJTA = Woodcock-Johnson Test of achievement; IGDIs = Individual Growth and Developmental Indicators; DLL = dual language learners; CTOPP = Comprehensive Test of Phonological Processing; TOPP-S = Test of Phonological Processing-Spanish; IDEL = Indicadores Dinámicos del Éxito en La Lectura; Pre-CTOPP = Preschool Comprehensive Test of Phonological Processing; W-MLS=Woodcock-Muñoz Language Survey.

The phonological awareness skills targeted during instruction varied across studies. Common phonological awareness targets included rhyming, blending, syllable awareness, and phoneme segmentation. Of the 17 studies, six measured phonological awareness gains in both English and Spanish (Barnett, Yarosz, Thomas, Jung, & Blanco, 2007; Farver, Lonigan, & Eppe, 2009; Gerber et al., 2004; Vaughn, Cirino, et al., 2006; Vaughn, Linan-Thompson, et al., 2006; Vaughn, Mathes, et al., 2006 ). All but one of these six studies (Vaughn, Mathes, et al., 2006) delivered phonological awareness instruction in Spanish and English.

Judging the Overall Quality of Studies by Rating

Visual displays resembling Consumer Reports are presented in Tables 2 and 3. Studies can be evaluated by examining the number of white (exemplary = 4) or partially white (acceptable = 3) circles in comparison with the circles that are partially black (minimal = 2) or black (unacceptable = 1) for each quality indicator. An average rating of all the quality indicators can be found in the first column for each study. For example, Table 3 illustrates that Roberts and Neal’s (2004) study investigating the effects of an English intervention targeting phonological awareness and alphabet knowledge received an average rating of 2.53 (maximum = 4).

In total, 58% of the studies (10 of 17) earned an average rating of 2.5 or higher, meaning their ratings overall were in the minimal to acceptable range. The average ratings ranged from an average rating of 1.86 (Healy, Vanderwood, & Edelston, 2005) to 3.07 (Farver et al., 2009). The average rating by types of intervention was slightly higher for Curriculum-based (M = 2.79), followed by Phonological Awareness + Alphabet Knowledge (M = 2.39) and Phonological Awareness-only (M = 2.20). The average rating by language of instruction was highest for the Spanish interventions (M = 2.57), followed by the English language interventions (M = 2.44) and the bilingual interventions (M = 2.39). These averages should be interpreted with caution as there were many more English-only studies than bilingual or Spanish-only studies. Most studies failed to report measures of generalization and maintenance, or social validity. Only two studies (Calhoon, Al Otaiba, Cihak, King, & Avalos, 2007; Calhoon, Al Otaiba, Greenberg, King, & Avalos, 2006) reported the extent of consumer satisfaction.

Studies receiving the lowest ratings (Healy et al., 2005; Linan-Thompson, Bryant, Dickson, & Kouzekanani, 2005; Quiroga, Lemos-Britton, Mostafapour, Abbott, & Berninger, 2002) typically had minimal or unacceptable ratings not only on their measures of external validity, but on their design characteristics as well. For example, the Linan-Thompson et al. (2005) group design study lacked randomization, did not demonstrate group equivalence, provided only operational definitions of its measures, and did not report how reliability was calculated. Limitations in its design characteristics reduced the internal validity of the study and diminished confidence in the study results. Similarly, the single-subject design study by Healy and colleagues (2005) earned a low-average rating because it did not establish a steady baseline, used an AB design, and did not describe its visual analysis. Although the children in this study made gains in their intervention, the limitations in the study’s design affected researchers’ ability to interpret findings with confidence.

Effect Size Estimates

Tables 3 and 4 contain a column with effect size estimates for group design and single-subject designs, respectively. For the group design studies, Cohen’s d was calculated for 13 of the 15 group design studies. The effect sizes could not be calculated for one study due to limitations in the data provided (Quiroga et al., 2002). Although Cohen’s d could not be calculated for the Barnett et al. (2007) study, the authors provided an R² value corresponding to a medium effect size in Spanish and English. An effect size could be calculated for only one of the two single-subject design studies (Gyovai, Cartledge, Kourea, Yurick, & Gibson, 2009), whose results yielded a Tau-U effect size of 52%, indicating questionable effects.

Types of Intervention

Looking across types of interventions, studies investigating the effects of Curriculum-Based approaches resulted in effect sizes ranging from small to large (Table 5). One study resulted in small effects (Calhoon et al., 2007), two studies had moderate effects (Barnett et al., 2007; Han, Vukelich, Buell, & Meacham, 2014), one had large effects (Vaughn, Mathes, et al., 2006), and four yielded mixed effects (Farver et al., 2009; Linan-Thompson et al., 2005; Vaughn, Cirino, et al., 2006; Vaughn, Linan-Thompson, et al., 2006). Studies that explicitly taught the phonological awareness skills assessed as outcome measures led to the highest effect sizes (Vaughn, Mathes, et al., 2006). The Barnett et al. (2007) and Han et al. (2014) studies yielded moderate effect sizes when using commercially available curricula such as High Scope and Creative Curriculum. It should be noted, however, that although children who were DLL in the Han et al. (2014) study made gains, they remained below their monolingual peers by the end of second grade. These researchers targeted rhyming in kindergarten, and phoneme segmentation in first grade.

Studies evaluating the effects of Phonological Awareness + Alphabet Knowledge instruction yielded mixed results. Two studies resulted in a small effect sizes (Gyovai et al., 2009; Roberts & Neal, 2004), one study yielded moderate effects (Linan-Thompson et al., 2005), one study resulted in large effects (Calhoon et al., 2006), one study had mixed effects across different phonological awareness outcomes (Solari & Gerber, 2008), and the effect sizes of one of the studies (Quiroga et al., 2002) could not be calculated. The Calhoon et al. (2006) study investigated the effects of providing first grade Latino students who are DLL with peer-assisted instruction targeting letter sounds, segmentation, and decoding. Children receiving this intervention made gains on the DIBELS Phoneme Segmentation and Nonword Fluency subtests. The Solari and Gerber (2008) study, which targeted phonemic segmenting and blending and phonics training, produced a large effect for initial sound identification, but small effects for sound omission and blending. The Roberts and Neal (2004) study had the weakest effects. This intervention targeted preschoolers and taught letter knowledge, letter writing, and rhyming. Although the children in this study made gains in letter knowledge, their rhyming skills did not improve significantly.

Because only three studies investigated the effects of Phonological Awareness-only instruction, determining the effects of this approach is premature. Two studies had mixed effects across phonological awareness tasks (Gerber et al., 2004; Leafstedt, Richards, & Gerber, 2004), and the effects of one study could not be calculated (Healy et al., 2005). The Leafstedt et al. (2004) study investigated the effects of an intervention targeting onset-rime identification and segmentation on kindergartener’s phonological awareness skills. The effects for this study were large for onset-rime identification, but moderate for segmentation, a phonological awareness skill the authors described as later developing.

Language of Instruction

We also evaluated the effects of studies by language of instruction. For the studies that only delivered instruction in English (see Tables 3 and 4), two studies had small effects (Gyovai et al., 2009; Roberts & Neal, 2004), two had moderate effects (Han et al., 2014; Linan-Thompson, Vaughn, Hickman-Davis, & Kouzekanani, 2003), three had large effects (Calhoon et al., 2006; Vaughn, Mathes, et al., 2006), two had mixed results (Leafstedt et al., 2004; Solari & Gerber, 2008), and the effects of one study could not be calculated (Healy et al., 2005). Only Vaughn, Mathes, et al. (2006) measured the Spanish phonological awareness gains of Latino DLLs when providing English-only instruction. First grade Latino children receiving English-only instruction targeting phoneme discrimination, segmenting, and blending made large gains in English, and in Spanish on the CTOPP.

The bilingual interventions yielded mixed effect sizes (see Table 3). One study resulted in small effects (Calhoon et al., 2007), one yielded moderate effects (Barnett et al., 2007), three led to mixed effects (i.e., effect sizes were not equal across languages; Gerber et al., 2005; Farver et al., 2009; Vaughn, Cirino, et al., 2006), and the effect size of one of the studies could not be calculated (Quiroga et al., 2002). Farver et al. (2009) and Vaughn, Cirino, et al. (2006) found that children receiving phonological awareness instruction in both languages made gains in Spanish, while still acquiring phonological awareness skills in English. In both studies, children receiving bilingual instruction made greater gains in Spanish than their peers who received English-only instruction. However, children’s phonological awareness gains across their two languages were not equivalent. For example, in the Farver et al. (2009) study, preschoolers showed moderate gains in Spanish and mixed gains in English.

The effects of the two studies investigating phonological awareness instruction in Spanish were also mixed (Linan-Thompson et al., 2005; Vaughn, Linan-Thompson, et al., 2006) (Table 2). The Linan-Thompson et al. (2005) study targeting Spanish phonological awareness skills (segmenting, blending) and phonics led to moderate gains in Spanish initial sound identification, but the gains on blending and sound omission were small. In contrast, the Vaughn, Linan-Thompson et al. (2006) intervention, Lectura Proactiva, targeting alphabet knowledge, text comprehension, and oral language skills led to large phonological awareness gains in Spanish, and moderate gains in English. These promising results highlight the need for further investigation of the effects of delivering phonological awareness instruction in Spanish to children who are DLL.

Discussion

As the number of Latino children who are DLL and are served by schools across the United States continues to rise (U.S. Census Bureau, 2011), it becomes even more crucial to carefully examine and evaluate the interventions designed to improve the educational outcomes of this population. Many Latinos who are DLL struggle to become proficient readers (Fuller, 2011), making it particularly timely to evaluate the current body of literature targeting reading instruction for this group of children. The findings from this systematic review not only provide an overview of the distribution, quality, and effects of existing phonological awareness intervention for these children, but they also provide important, general implications for conducting adequate interventions and research for Latino children who are DLL.

Distribution, Quality, and Effects of PA Interventions for Latino Children Who Are DLL

Distribution of studies

The first aim of this systematic review was to determine the distribution of existing phonological awareness interventions for Latino children who are DLL. The findings from the systematic review indicate that most phonological awareness interventions were Curriculum-Based, that very few interventions targeted preschoolers, and that most interventions were conducted only in English. These findings are surprising, given our contemporary understanding of effective phonological awareness interventions (Ehri et al., 2001; Shanahan & Lonigan, 2010) and our knowledge regarding the best practices for delivering interventions to children who are DLL (Castro et al., 2011; López & Greenfield, 2004).

This review reveals that only four studies have specifically examined the effects of providing phonological awareness interventions to Latino preschoolers who are DLL (Barnett et al., 2007; Farver et al., 2009; Han et al., 2014; Roberts & Neal, 2004). This is a notable finding because phonological awareness is a common metric of preschoolers’ school readiness (La Paro & Pianta, 2000) and a popular learning objective on widely used early childhood curricula such as Creative Curriculum and High Scope. Almost half of Latino preschoolers enter kindergarten with reduced phonological awareness skills in English and Spanish, placing them at greater risk for persisting reading difficulties (Fuller, 2011). But as the current literature stands, the bulk of phonological awareness interventions for preschoolers are based on monolingual children (Ehri et al., 2001), leaving practitioners ill-equipped to provide early, preventive phonological awareness interventions for Latino preschoolers during a crucial period of their development. The findings from this review indicate the urgency for future research focusing on the effects of phonological awareness interventions for Latino preschoolers who are DLL.

Another significant finding is that most phonological awareness interventions for Latino children who are DLLs were only conducted in English. Although this review revealed that Latino children can make positive phonological awareness gains when interventions are delivered only in English, Pollard-Durodola and Simmons (2009) propose that the goal of interventions for Latino DLL should not only be to attain English academic success, but also to promote their biliterate and bilingual development. Because phonological awareness skills are highly interrelated across children’s two languages, López and Greenfield (2004) and Anthony and colleagues (2011) recommend promoting Latino children’s bilingual acquisition of phonological awareness skills by delivering the interventions in Spanish, or by supporting English phonological awareness instruction with Spanish. These recommendations are aligned with the Revised Linguistic Interdependence Hypothesis (Verhoeven, 2007), which postulates that DLL children with strong phonological awareness skills in one language can apply these skills to their second language. Despite these recommendations, only two studies in this review delivered the phonological awareness interventions in Spanish (Linan-Thompson et al., 2005; Vaughn, Linan-Thompson, et al., 2006), and only Vaughn and colleagues measured whether children applied the phonological awareness skills they learned in Spanish to English after receiving Spanish-only intervention. These findings indicate a need for future DLL research to empirically measure whether providing Latino children with only Spanish phonological awareness interventions yields phonological awareness gains in their two languages. Findings from these studies will potentially increase our knowledge regarding DLL children’s bilingual literacy development.

Quality of studies

The second objective of this review was to determine the quality of existing phonological awareness interventions for children who are DLL. Most studies demonstrated strengths in their design and statistical analyses. However, few included measures of generalization (Gerber et al., 2004; Han et al., 2014) and social validity (Calhoon et al., 2007; Calhoon et al., 2006). Including measures of generalizations is important because the long-term effects of providing children who are DLL with instruction in English, Spanish, or both languages remains largely unexplored. Although some scholars assert the academic and social benefits of supporting DLL children’s language and literacy development in both languages (Bialystok & Feng, 2011), few studies have examined the long-term impact of language of instruction. Longitudinal studies are needed to increase our knowledge of typical dual language and literacy development in children who are DLL, as well as to inform policy makers about ways to reduce the persisting achievement gap in this population.

Effects of studies

The third objective of this review was to evaluate the effects of phonological awareness interventions for Latino children who are DLL. Overall, the effects of these studies were positive, yielding small to large effects. However, limitations in these studies make it difficult to directly compare which type of intervention and language of instruction is most effective for Latino children who are DLL. These limitations include the following: (a) brief descriptions of the interventionists and participants in the studies, (b) insufficient information about how to specifically deliver phonological awareness interventions, (c) minimal information about how phonological awareness interventions were adapted from English to Spanish, (d) heterogeneity in the phonological awareness assessments used to measure outcome measures, and (e) inadequate descriptions of the type and quality of the language of instruction occurring in the classroom (e.g., two-way bilingual, English immersion, transitional).

Despite these limitations, individual examination of the studies’ effects indicate that phonological awareness interventions containing direct instruction (Calhoon et al., 2006; Vaughn, Mathes, et al., 2006) resulted in the largest phonological awareness gains, regardless of type of intervention (i.e., Curriculum-Based, Phonological Awareness + Alphabet Knowledge, Phonological Awareness-only) or language of instruction. These finding are in line with the best practice recommendations from the National Early Literacy Panel (Lonigan & Shanahan, 2009), which recommends providing explicit phonological awareness instruction. Like monolingual children, Latino children who are DLL benefit from interventions that incorporate explicit instruction of phonological awareness skills, guided practice, contingent feedback, and multiple response opportunities. The studies with large effects also applied intensive phonological awareness instruction, ranging from 2 to 5 times a week for a minimum of 15 min per session, and interventionists delivered instruction in small groups. These findings were contrary to the study resulting in the smallest effects (Roberts & Neal, 2004). Roberts and Neal targeted letter knowledge and rhyming during whole-group instruction. Rhyming was taught by having children identify rhyming pairs with minimal feedback and practice opportunities provided. The weak results in this study could be attributed to rhyming not being as salient in Spanish (Pollard-Durodola & Simmons, 2009), a lack of explicit instruction, and reduced practice opportunities.

The most interesting finding from this systematic review is that most bilingual phonological awareness interventions yielded mixed effects, meaning that the magnitude of phonological awareness gains were not equivalent across languages. These findings have significant implications for DLL research. Gottardo, Gu, Mueller, Baciu, and Pauchulo (2011) note that a potential reason for these mixed findings for DLL children’s gains across their two languages could result from studies’ conceptual limitations. These conceptual limitations include unavailable descriptions of child, teacher, and classroom factors that might influence bilingual phonological awareness outcomes, and the use of direct English translations to develop Spanish interventions and assessments. Peña and colleagues (2016) warn against directly translating curricula or assessments, as this can reduce the validity of bilingual studies. To illustrate, Gerber et al. (2004) directly translated its English curriculum and targeted sound segmentation and blending in Spanish. Sound-level manipulations are not as salient in Spanish (Jiménez González & García, 1995). This difference between English and Spanish could have potentially tampered the results. Although addressing these conceptual limitations is vital in moving the field of DLL research forward, it is not an easy feat. There continues to be a gap in our knowledge regarding English and Spanish phonological awareness development in Latino children who are DLL and in the availability of appropriate assessments for this population.

Implications for Future Research

The findings from this systematic review augment our current knowledge regarding the quality and effects of existing phonological awareness interventions for Latinos who are DLL in the early and primary grades. This review has limitations, however, including the following: (a) the studies reviewed were from a relatively narrow time window, (b) the diversity in outcome measures make it difficult to directly compare studies, and (c) the questions of for whom and under what conditions these phonological awareness interventions are most appropriate remain unanswered. Limitations in the body of literature reviewed include the following: (a) the potential influence of teacher, child, and classroom-level factors were not reported, (b) the nuances of language of instruction across studies could not be fully explored, and (c) most of the Spanish phonological awareness interventions and assessments reviewed were direct English translations.

Despite these limitations, this systematic review illuminates current gaps in the literature, informing future research directions. These future directions include the following: (a) increasing the number of studies focusing on evaluating the effects of phonological awareness interventions for Latino preschoolers, (b) evaluating the effects of providing phonological awareness interventions in Spanish, (c) developing more valid Spanish phonological awareness assessments and interventions that take the language characteristics of Spanish in consideration, (d) exploring the interrelationship of DLL children’s phonological awareness skills across their two languages, and (e) conducting more longitudinal studies to better understand the bilingual and biliterate development of children who are DLL. Most notably, it is critical to continue identifying efficacious literacy-based interventions that are mindful of DLLs’ unique language, social, and academic needs.

Implications for Practice

Although the extant body of literature on effective phonological awareness interventions for Latino children who are DLL in the early and primary grades is limited, the results of this systematic review can be applied to provide practitioners with guidelines to help improve the phonological awareness skills of children who are DLL. Specifically, practitioners should

Provide children with phonological awareness interventions that contain direct instruction which is explicit and systematic, allowing for multiple response opportunities and contingent feedback.

Deliver intensive phonological awareness interventions in small groups for children who might be falling behind their peers.

Include phonological awareness instruction in early childhood settings to ensure children are not falling behind upon entering kindergarten.

Learn about the language differences between English and Spanish to avoid direct translations of phonological awareness curricula or assessments.

Support children’s acquisition of phonological awareness skills in both languages to promote their biliterate development.

Target phonological awareness skills that are salient in Spanish (i.e., syllable awareness rather than phonemic awareness) when the phonological awareness intervention is in Spanish.

Footnotes

Authors’ Note

The adaptation of the Consumer Reports graphical model in this article does not indicate any endorsement by or affiliation with Consumer Reports®. Consumers Union was not involved in any way in the creation, production, or application of the evaluation framework or ratings described in the article.

Declaration of Conflicting Interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

ORCID iD

Xigrid Soto

References

Anthony

J. L.

Williams

J. M.

Durán

L. K.

Gillam

S. L.

Liang

Aghara

. . . Landry

S. H.

(2011). Spanish phonological awareness: Dimensionality and sequence of development during the preschool and kindergarten years. Journal of Educational Psychology, 103, 857-876.

Baker

D. L.

Cummings

K. D.

Good

R. H. Y.

Smolkowski

(2007). Indicadores Dinámicos del Éxito en La Lectura (IDEL®): Summary of decision rules for intensive, strategic, and benchmark instructional recommendations in kindergarten through third grade. Eugene, OR: Dynamic Measurement Group.

Barnett

W. S.

Yarosz

D. J.

Thomas

Jung

Blanco

(2007). Two-way and monolingual English immersion in preschool education: An experimental comparison. Early Childhood Research Quarterly, 22, 277-293.

Bialystok

Feng

(2011). Language proficiency and its implications for monolingual and bilingual children. In Durgunoğlu

A. Y.

Goldenberg

(Eds.), Language and literacy development in bilingual settings (pp. 121-138). New York, NY: Guilford Press.

Buysse

Peisner-Feinberg

Páez

Hammer

C. S.

Knowles

(2014). Effects of early education programs and practices on the development and learning of dual language learners: A review of the literature. Early Childhood Research Quarterly, 29, 765-785.

Byrne

(2014). The foundation of literacy: The child’s acquisition of the alphabetic principle. East Suxxes, UK: Psychology Press.

Calhoon

M. B.

Al Otaiba

Cihak

King

Avalos

(2007). Effects of a peer-mediated program on reading skill acquisition for two-way bilingual first-grade classrooms. Learning Disability Quarterly, 30, 169-184.

Calhoon

M. B.

Al Otaiba

Greenberg

King

Avalos

(2006). Improving reading skills in predominantly Hispanic Title 1 first-grade classrooms: The promise of peer-assisted learning strategies. Learning Disabilities Research & Practice, 21, 261-272.

Castro

D. C.

Páez

M. M.

Dickinson

D. K.

Frede

(2011). Promoting language and literacy in young dual language learners: Research, practice, and policy. Child Development Perspectives, 5, 15-21.

10.

Cohen

(1992). Statistical power analysis. Current Directions in Psychological Science, 1(3), 98-101.

11.

Dickinson

D. K.

McCabe

Clark-Chiarelli

Wolf

(2004). Cross-language transfer of phonological awareness in low-income Spanish and English bilingual preschool children. Applied Psycholinguistics, 25, 323-347.

12.

Durán

L. K.

Roseth

C. J.

Hoffman

(2010). An experimental study comparing English-only and transitional bilingual education on Spanish-speaking preschoolers’ early literacy development. Early Childhood Research Quarterly, 25, 207-217.

13.

Durgunoğlu

A. Y.

Nagy

W. E.

Hancin-Bhatt

B. J.

(1993). Cross-language transfer of phonological awareness. Journal of Educational Psychology, 85, 453-465.

14.

Ehri

L. C.

Nunes

S. R.

Willows

D. M.

Schuster

B. V.

Yaghoub-Zadeh

Shanahan

(2001). Phonemic awareness instruction helps children learn to read: Evidence from the National Reading Panel’s meta-analysis. Reading Research Quarterly, 36, 250-287.

15.

Farver

J. A. M.

Lonigan

C. J.

Eppe

(2009). Effective early literacy skill development for young Spanish-speaking English language learners: An experimental study of two methods. Child Development, 80, 703-719.

16.

Fuller

(2011, June 21). The “silent crisis” of the Latino dropout rate. NEA Today. Retrieved from http://neatoday.org/2011/06/the-silent-crisis-of-the-latino-dropout-rate-2/

17.

Gerber

Jimenez

Leafstedt

Villaruz

Richards

English

(2004). English reading effects of small-group intensive intervention in Spanish for K–1 English learners. Learning Disabilities Research & Practice, 19, 239-251.

18.

Gersten

Fuchs

L. S.

Compton

Coyne

Greenwood

Innocenti

M. S.

(2005). Quality indicators for group experimental and quasi-experimental research in special education. Exceptional Children, 71, 149-164.

19.

Goldstein

Lackey

K. C.

Schneider

N. J.

(2014). A new framework for systematic reviews: Application to social skills interventions for preschoolers with autism. Exceptional Children, 80, 262-286.

20.

Gorman

B. K.

Gillam

R. B.

(2003). Phonological awareness in Spanish: A tutorial for speech-language pathologists. Communication Disorders Quarterly, 25, 13-22.

21.

Gottardo

Mueller

Baciu

Pauchulo

A. L.

(2011). Factors affecting the relative relationships between first- and second-language phonological awareness and second language reading. In Durgunoglu

A. Y.

Goldenberg

(Eds.), Language and literacy development in bilingual settings (pp. 141-167). New York, NY: Guilford Press.

22.

Gyovai

L. K.

Cartledge

Kourea

Yurick

Gibson

(2009). Early reading intervention: Responding to the learning needs of young at-risk English language learners. Learning Disability Quarterly, 32, 143-162.

23.

Han

Vukelich

Buell

Meacham

(2014). Beating the odds: A longitudinal investigation of low-income dual-language and monolingual children’s English language and literacy performance. Early Education and Development, 25, 841-858.

24.

Healy

Vanderwood

Edelston

(2005). Early literacy interventions for English language learners: Support for an RTI model. The California School Psychologist, 10, 55-63.

25.

Horner

R. H.

Carr

E. G.

Halle

McGee

Odom

Wolery

(2005). The use of single-subject research to identify evidence-based practice in special education. Exceptional Children, 71, 165-179.

26.

Jiménez González

J. E.

García

C. R. H

. (1995). Effects of word linguistic properties on phonological awareness in Spanish children. Journal of Educational Psychology, 87, 193-201.

27.

Kaminski

R. A.

Smith

Laimon

(2002). DIBELS: Dynamic Indicators of Basic Early Literacy Skills ( Good

R. H.

, Ed.). Eugene, OR: Dynamic Measurement Group.

28.

Kratochwill

T. R.

Hitchcock

J. H.

Horner

R. H.

Levin

J. R.

Odom

S. L.

Rindskopf

D. M.

Shadish

W. R.

(2012). Single-case intervention research design standards. Remedial and Special Education, 34, 26-38.

29.

La Paro

K. M.

Pianta

R. C

. (2000). Predicting children’s competence in the early school years: A meta-analytic review. Review of Educational Research, 70, 443-484.

30.

Leafstedt

J. M.

Richards

C. R.

Gerber

M. M.

(2004). Effectiveness of explicit phonological-awareness instruction for at-risk English learners. Learning Disabilities Research & Practice, 19, 252-261.

31.

Linan-Thompson

Bryant

D. P.

Dickson

S. V.

Kouzekanani

(2005). Spanish literacy instruction for at-risk kindergarten students. Remedial and Special Education, 26, 236-244.

32.

Linan-Thompson

Vaughn

Hickman-Davis

Kouzekanani

(2003). Effectiveness of supplemental reading instruction for second-grade English language learners with reading difficulties. The Elementary School Journal, 103, 221-238.

33.

Lonigan

C. J.

Shanahan

(2009). Executive summary: Developing early literacy: Report of the National Early Literacy Panel. Retrieved from https://files.eric.ed.gov/fulltext/ED508381.pdf

34.

López

L. M.

Greenfield

D. B.

(2004). The cross-language transfer of phonological skills of Hispanic Head Start children. Bilingual Research Journal, 28(1), 1-18.

35.

McConnell

Bradfield

Wackerle-Hollman

Rodriguez

(2012). Individual growth and development indicators of early literacy. Saint Paul, MN: Early Learning Labs.

36.

National Research Council. (2006, Summer). Hispanics in America. InFocus, 6(2). Retrieved from http://www.infocusmagazine.org/6.2/bsoc_hispanics_in_america.html

37.

Parker

R. I.

Vannest

K. J.

Davis

J. L.

Sauber

S. B.

(2011). Combining nonoverlap and trend for single-case research. Tau-U. Behavior Therapy, 42, 284-299.

38.

Peña

E. D.

Bedore

L. M.

Kester

E. S.

(2016). Assessment of language impairment in bilingual children using semantic tasks: Two languages classify better than one. International Journal of Language & Communication Disorders, 51, 192-202.

39.

Pollard-Durodola

S. D.

Simmons

D. C.

(2009). The role of explicit instruction and instructional design in promoting phonemic awareness development and transfer from Spanish to English. Reading & Writing Quarterly, 25, 139-161.

40.

Quiroga

Lemos-Britton

Mostafapour

Abbott

R. D.

Berninger

V. W.

(2002). Phonological awareness and beginning reading in Spanish-speaking ESL first graders: Research into practice. Journal of School Psychology, 40, 85-111.

41.

Rakap

(2015). Effect sizes as result interpretation aids in single-subject experimental research: Description and application of four nonoverlap methods. British Journal of Special Education, 42, 11-33.

42.

Roberts

Neal

(2004). Relationships among preschool English language learner’s oral proficiency in English, instructional experience and literacy development. Contemporary Educational Psychology, 29, 283-311.

43.

Shanahan

Lonigan

C. J.

(2010). The National Early Literacy Panel: A summary of the process and the report. Educational Researcher, 39, 279-285.

44.

Solari

E. J.

Gerber

M. M.

(2008). Early comprehension instruction for Spanish-speaking English language learners: Teaching text-level reading skills while maintaining effects on word-level skills. Learning Disabilities Research & Practice, 23, 155-168.

45.

Storch

S. A.

Whitehurst

G. J.

(2002). Oral language and code-related precursors to reading: Evidence from a longitudinal structural model. Developmental Psychology, 38, 934-947.

46.

U.S. Census Bureau. (2011). The Hispanic population 2010: 2010 census briefs. Retrieved from https://www.census.gov/content/dam/Census/library/publications/2011/dec/c2010br-04.pdf

47.

Vannest

K. J.

Parker

R. I.

Gonen

Adiguzel

(2016). Single case research: Web based calculators for SCR analysis (Version 2.0) [Web-based application]. College Station: Texas A&M University. Retrieved from www.singlecaseresearch.org/calculators/tau-u

48.

Vaughn

Cirino

P. T.

Linan-Thompson

Mathes

P. G.

Carlson

C. D.

Hagan

E. C.

. . . Francis

D. J.

(2006). Effectiveness of a Spanish intervention and an English intervention for English-language learners at risk for reading problems. American Educational Research Journal, 43, 449-487.

49.

Vaughn

Linan-Thompson

Mathes

P. G.

Cirino

P. T.

Carlson

C. D.

Pollard-Durodola

S. D.

. . . Francis

D. J.

(2006). Effectiveness of Spanish intervention for first-grade English language learners at risk for reading difficulties. Journal of Learning Disabilities, 39, 56-73.

50.

Vaughn

Mathes

Linan-Thompson

Cirino

Carlson

. . . Francis

(2006). Effectiveness of an English intervention for first-grade English language learners at risk for reading problems. The Elementary School Journal, 107, 153-180.

51.

Verhoeven

(2007). Early bilingualism, language transfer, and phonological awareness. Applied Psycholinguistics, 28, 425-439.

52.

Wagner

R. K.

Torgesen

J. K.

Rashotte

C. A.

Pearson

N. A.

(2013). CTOPP-2: Comprehensive Test of Phonological Processing. Austin, TX: Pro-Ed.

53.

What Works Clearinghouse. (2018). Procedures and standards handbook: Version 3. Retrieved from https://ies.ed.gov/ncee/wwc/Handbooks

54.

Woodcock

R. W.

McGrew

K. S.

Mather

(2001). Woodcock-Johnson III Tests of Achievement. Itasca, IL: Riverside.