Abstract
German, D. G., Schwanke, J. H., & Ravid, R. (2012). Word finding difficulties: Differentiated vocabulary instruction in the speech and language room. Communication Disorders Quarterly, 33, 146–156.
Introduction
Word finding (WF) is an aspect of vocabulary skill. As many as 25% of learners with specific language impairment (SLI) have been predicted to have word finding difficulties (WFD), and 49% of students with learning disabilities have been reported to have WFD (Messer & Dockrell, 2006). Many students with reading difficulties also have WFD (Messer, Dockrell, & Murphy, 2004). WFD can result in significant expressive language problems that interfere with communication and can impede learning (German, 2005). A number of validated vocabulary intervention programs have been effective for most learners, but their focus on learning semantic representations of words may not be enough for learners with WFD. Often, students with WFD are not successful in bridging their newly learned vocabulary and their lexical access skills. They thus have difficulty retrieving learned words in school assessments (German, 2005).
In this study, the authors explored whether students who already had an individualized education program (IEP) for WF would be more successful in their vocabulary learning if they received vocabulary instruction that linked the semantic and phonological aspects of vocabulary. Child language research has suggested that the etiology of WFD may be semantic based (Messer & Dockrell, 2006) and/or form based (Constable, Stackhouse, & Wells, 1997; Sheng & McGregor, 2010), depending on the nature of the learner’s WFD and the lexical factors of the vocabulary being learned (German & Newman, 2004). Vocabulary instruction in school is most often focused on developing learners’ semantic representations of words. Based on this research, the authors created a differentiated approach to vocabulary instruction that incorporated both semantic and phonological treatments to anchor school vocabulary for meaningful and automatic usage. To measure the efficacy of this method of vocabulary instruction in school contexts, students’ vocabulary learning was compared when provided a semantic-based (S) approach only to vocabulary instruction versus a semantic- and phonological-based (S & P) approach. The authors asked the following questions:
Will a S & P approach to vocabulary instruction be beneficial for learners with WFD as an intervention in a Response to Intervention (RTI)-Tier 2 classroom or RTI-Tier 3 pullout program?
Will the lexical factors of vocabulary (frequency of occurrence, phonotactic probability, and word length) taught influence learners’ success with either the S or S & P approaches to vocabulary instruction?
The Study
Participants comprised two groups of students with WFD: 3 boys and 3 girls in Group A and 2 boys and 2 girls in Group B. Students were enrolled in second grade and ranged in age from 7 years 11 months to 8 years 9 months. All had an IEP with goals and benchmarks for WF intervention and were receiving ongoing language therapy from the school speech-language pathologist (SLP). All 10 students scored within 1 standard deviation of the mean on the Peabody Picture Vocabulary Test, Fourth Edition (Dunn & Dunn, 2007), and all but 1 student scored within 1 standard deviation of the mean on the Receptive and Expressive subtests of the Clinical Evaluation of Language Function, Fourth Edition (Semel, Wiig, & Secord, 2003). Students’ WF skills were assessed using the Test of Word Finding–Second Edition (TWF-2; German, 2000). Each participant had a WF quotient (WFQ) below 90, indicating weak WF skills on the TWF-2.
The authors used a single-group pretest–posttest design in which students served as their own control. During the vocabulary instruction phase, the 10 participants were seen for 30 min, twice a week by their school SLP. Students were seen in two language groups. Each week, 5 words were taught to each group. For 2 weeks, the school SLP used S vocabulary instruction to teach 10 words to the students. The following 2 weeks, the school SLP used the S & P approach to vocabulary instruction to teach the other 10 words. The S teaching approach was used first to ensure that students would not inadvertently use form-based strategies learned in the S & P approach when being taught using the S approach to vocabulary instruction. Students’ vocabulary learning (receptive and expressive) were compared after being taught via the two instructional approaches. Receptive vocabulary knowledge was assessed with multiple choice items, and expressive vocabulary knowledge was assessed by naming and fill-in-the-blank tasks.
Four pretest scores were generated for each student: a receptive pretest score and an expressive pretest score on the words that were taught during Weeks 1 and 2, and a receptive pretest score and an expressive pretest score on the words that were taught during Weeks 3 and 4. During the posttest phase, four additional sets of posttest receptive and expressive scores were created for each student. Students were tested at the end of each week of instruction, and their scores from Weeks 1 and 2 (S approach) were combined, as were their scores from Weeks 3 and 4 (S & P approach). Finally, in a maintenance phase 3 weeks post-study, students’ receptive and expressive skills were again tested to generate postintervention maintenance scores.
A total of 20 second grade vocabulary words from the curriculum were taught: 10 science words and 10 math words (e.g., experiment, geometry, vibration, humidity). These curriculum words were considered challenging to access because of their phonological complexity. The list consisted primarily of bisyllabic and multisyllabic words. The science and math words were matched for syllabic structure. Students’ difficulty with these words was verified by their low receptive and expressive pretest scores.
Semantic-based vocabulary instruction
During the first 2 weeks, both language groups were taught using the S approach to vocabulary instruction. Students received explicit instruction as to word meanings and applications.
The word was introduced and its academic context was indicated (“Experiment, this is a science word that you are all studying”).
Student-friendly explanations were presented to explain the meaning of each word (“Experiment means a test or trial, a test you do to find out something you did not know before”).
Visual and verbal examples of the target word referent or meaning (“A test to see whether people would choose to eat green pizza is an experiment”), and nonexamples of the target word referent or meaning (“A test to see whether the Cubs will win is not an experiment”) were shared in various contexts.
To check understanding, students were asked to find in the room, demonstrate, or verbalize examples of the word’s meaning (students were asked to think of a test that would be an experiment).
Semantic- and phonological-based vocabulary instruction
In Weeks 3 and 4, the S & P approach to vocabulary instruction was implemented. This involved the teaching of both word meanings (lessons like that taught in the S approach) and form-based strategies. Three form-based strategies used were as follows:
Metalinguistic reinforcement. The metalinguistic strategies focused on reinforcing the phonological structure of multisyllabic words, the syllabic frame, and the segmental sound units. The words were written as a whole and then written in syllables in a grid. Students first counted the number of syllables as they said the words and then repeated each syllable after the SLP while tapping their head, shoulders, knees, and toes. Special emphasis was put on those syllables a learner may have difficulty accessing. For example, if the second or third syllable of a word was vague for a learner, syllable dividing for WF would put more emphasis on those evasive syllables (experiment would be segmented focusing on the second and third syllables, ex PER I ment, if they were the evasive syllables; German, 2005).
Same-sounds mnemonic cue. Students learned to associate a mnemonic cue with the word or its syllable(s). The mnemonic cues selected were cue words similar in sound to the word or syllables (same-sounds cues: X spear mint for experiment; German, 2002, 2005). To avoid reinforcing pathways to the cue instead of the target, students were instructed to think of the cue word, but not say it, prior to verbalizing the word. Students’ cue words were entered into a “think-call-out” or “think bubble” on the S & P work sheet to emphasize that they were to think of the cue prior to saying the word or syllable.
Word rehearsal. To strengthen and stabilize word pathways, learners were asked to think of their same-sounds mnemonic cues (X spear mint) before they verbalized the word 3 times in isolation (experiment, experiment, experiment) and then in sentences and discourse (we did an experiment in science) to increase automaticity of word retrieval in oral and written language.
Results/Discussion
Question 1: Will an S & P approach to vocabulary instruction be beneficial for learners with WFD?
Vocabulary instruction in the SLP language room was enhanced for learners with WFD when phonological strategies were embedded in the teaching paradigm; learners’ ability to access studied vocabulary was much improved following the instructional approach that focused on both the semantic and phonological properties of words rather than on semantics alone.
The gap between students’ receptive and expressive skills for studied vocabulary was less after receiving the S & P approach to vocabulary instruction.
At 3 weeks post-intervention, learners with WFD were still able to access studied vocabulary, suggesting that the S & P approach had a sustained effect.
Question 2: Will the lexical factors of vocabulary taught influence learners’ success with either the S or S & P approaches to vocabulary instruction?
Neither word frequency nor word length significantly affected students’ naming of the words they learned via either of the two vocabulary approaches.
But the findings indicate that a word’s phonology (phonotactic probability—the frequency of which sounds occur in the language) did influence students’ success in retrieving studied words. Learners found it easier to automatically name those academic words consisting of common phoneme sequences, whereas words containing rarer sound sequences were more difficult to name.
Study findings indicate that students with WFD may find it easier to apply form-based strategies to words that contain more common phonological sequences.
Adding phonological strategies to semantic strategies when teaching vocabulary facilitated students’ learning and retrieval of vocabulary words. Students find words with familiar phonological sequences of phonemes easier to learn than words that have low phonotactic probably, that is, words with unfamiliar phoneme sequences. Consequently, words with low phonotactic probability will likely require additional attention in the S&A approach if learners are to become automatic in their use. The authors suggest that SLPs could first teach those words that contain the most common phonological sequences (high phonotactic probability). Then once learners experience success with these words, they follow with S & P vocabulary instruction on the words with rarer sound sequences. In this way, previous paradigm learning can boost new learning on words thought to be more difficult.