Keeping up with the evidence base: Survey of behavior professionals about Naturalistic Developmental Behavioral Interventions

Abstract

Professionals who primarily deliver services to children on the autism spectrum employ a range of techniques and supports that are colloquially known as applied behavior analysis therapy. The landscape of evidence supporting interventions for children on the autism spectrum has vastly transformed in the last decade. A substantial, relatively high-quality literature base supports the effectiveness of Naturalistic Developmental Behavior Interventions for supporting development in children on the autism spectrum, yet few professionals serving this population receive training in this category of interventions. Board Certified Behavior Analysts and related professionals are the primary service providers for this population. The purpose of this survey study is to describe and understand the knowledge and beliefs that Behavior Analyst Certification Board certificants have around Naturalistic Developmental Behavior Interventions, and the implications for training the professionals most likely to serve young children on the autism spectrum. A total of 901 respondents completed the survey. Respondents indicated, on average, little to no knowledge of Naturalistic Developmental Behavior Intervention practices and that few believe these practices to be effective or appropriate for the field. We discuss the implications and needs for future training and research in this area.

Lay abstract

Primary service providers for young children on the autism spectrum and developmentally delayed children use many strategies under the umbrella of applied behavior analysis therapy. The evidence supporting interventions for children on the autism spectrum has changed last decade, and powerful research supports the relative effectiveness of Naturalistic Developmental Behavior Interventions, yet a few professionals serving young children on the autism spectrum receive training in this category of interventions. Board Certified Behavior Analysts and related professionals are the primary service providers for this population. The purpose of this survey study is to describe and understand the knowledge and beliefs that Behavior Analyst Certification Board certificants have around Naturalistic Developmental Behavior Interventions. The survey was completed by 901 respondents. Respondents indicated, on average, little to no knowledge of Naturalistic Developmental Behavior Intervention practices and few believe that these practices are effective or appropriate for the field. Recommendations include increasing training opportunities for related professionals, and changing certification requirements to match the current evidence.

Keywords

autism behavior analysis Behavior Analyst Certification Board Board Certified Behavior Analyst naturalistic Naturalistic Developmental Behavior Intervention survey

Behavior therapists are one of the leading service providers who provide supports to children on the autism spectrum,¹ with their numbers having grown considerably in the last 20 years (Xu et al., 2019). This growth accompanies a related increase in the demand for applied behavior analysis (ABA) therapy, which is the most commonly recommended intervention approach for this population (Reichow, 2012; Stahmer et al., 2005). Traditionally, ABA therapy encompasses a series of techniques that are based in operant theories of learning, ranging from focused intervention practices (Odom, Collet-Klingenberg, et al., 2010) such as discrete trial teaching (DTT) to comprehensive intervention (Odom, Boyd, et al., 2010) approaches such as early intensive behavioral intervention (EIBI). These interventions tend to be highly structured and adult-led, and leverage the use of trial-based learning and external motivation (i.e. edible rewards, stickers, etc.) to teach children discrete skills. Despite the frequency with which traditional behavioral interventions are provided to children on the spectrum, relatively a few high-quality studies attest to their effectiveness for supporting generalized development in this population (Reichow et al., 2012, 2018; Sandbank, Bottema-Beutel, Crowley, et al., 2020). Rather, recent meta-analyses have identified an alternative set of interventions, Naturalistic Developmental Behavioral Interventions (NDBIs), as one that has garnered more support from randomized controlled trials (RCTs; Sandbank, Bottema-Beutel, Crowley, et al., 2020; Tiede & Walton, 2019). NDBIs blend behavioral and developmental theories of learning. These teaching methods differ from traditional behavioral interventions in that the teaching targets are chosen from developmental sequences that emphasize the pivotal importance of early social communication skills, and the antecedents for learning trials are embedded in naturally occurring interactions, such that the child triggers opportunities for learning (Schreibman et al., 2015). While there are traditional behavioral interventions that are delivered in natural environments and rely on natural contingencies, such as Natural Environment Teaching (NET), therapists using these approaches often exert substantial control over the occasion of natural antecedents (i.e. by contriving repeated teaching opportunities), and their selection of instructional targets is rarely informed by early developmental sequences. Furthermore, NDBIs share several features that distinguish them from NET, including frequent therapist use of contingent imitation and targeted linguistic mapping and expansion (Schreibman et al., 2015). Despite these differences, NDBIs fully qualify as ABA techniques because they are conceptually consistent with behavioral principles of learning, have been described with high technological precision, are applied to socially important goals, meant to effect generalized developmental change, and are analytical in their implementation (relying on careful measurement of behavior and data-based decision making; Baer et al., 1968; Schreibman et al., 2015).

Currently, the Behavior Analyst Certification Board (BACB) maintains certification for over 42,000 Board Certified Behavior Analysts (BCBAs) and Board Certified Behavior Analysts with doctoral distinction (BCBA-D), over 4000 Board Certified Assistant Behavior Analysts (BCaBAs), and over 82,000 Registered Behavior Technicians (RBTs), with over 74% of total certificants reporting a primary area of professional emphasis in autism (BACB Certificant Data, n.d.). BCBAs, the graduate-level clinicians who primarily supervise RBTs and BCaBAs, train parents to implement strategies and programs, and plan the implementation of behavior analysis services, are trained and held to a 95-item task list of standards which outlines their training and scope of practice. However, despite the accumulation of relatively high-quality evidence supporting the effectiveness of NDBIs, the task list has no mention of NDBIs, and there are few/no widely available current training resources specifically for BACB certificants in any NDBI practice.

NDBIs are well-suited for uptake by BCBAs; many NDBIs have rigorous implementation fidelity checklists, incorporate teaching trials that fit squarely within a behavior analytic framework, and even include instruments to facilitate data collection. However, the developmental component of NDBIs provides a challenge for many BCBAs, who do not typically receive advanced training in developmental sequences (Blydenburg & Diller, 2016). Yet, BCBAs working with young children on the autism spectrum are often tasked with creating treatment plans that target early skills in areas such as play, speech, language, communication, and social skills. Without an in-depth understanding of early developmental sequences in these domains, behavior therapists often rely on popular ABA curriculum-based measures, such as the Verbal Behavior Milestones Assessment and Placement and Program (VB-MAPP), to plan the scope and sequence of instruction (Padilla, 2020), despite poor evidence of reliability and validity (Dixon et al., 2015).

Current study

Given that NDBIs qualify as ABA techniques, and that a relatively strong research base suggests their effectiveness for supporting development in autistic children, the primary population served by BACB certificants, it is important to understand the extent to which behavior professionals who primarily serve young children on the autism spectrum have learned and incorporate NDBI techniques into their practice. Thus, we sought to provide a snapshot of the current knowledge, beliefs, and practices employed by behavior professionals across training levels in this area. Our hope is that a greater understanding of the knowledge gaps and training needs of behavioral professionals will facilitate better uptake and use of NDBI practices in the field.

Research questions

This survey study was designed to address the following research questions:

RQ1. What do autism-focused behavior professionals know about NDBIs as an intervention approach for young children with developmental delays?

RQ2. What experience and training do autism-focused behavior professionals have regarding NDBIs as an intervention approach for young children with developmental delays?

RQ3. Which characteristics (age of client, training background) are more likely to be associated with NDBI familiarity and/or training?

RQ4. What beliefs do autism-focused behavior professionals hold regarding the implementation of NDBI strategies in early intervention?

Method

Distribution

In December 2019, we contacted the BACB to request survey distribution to their current certificate holders. Respondents from all locations meeting the following criteria were included (1) held an active certificate and (2) primary area of work includes infants/children on the autism spectrum or those with developmental delays. Distribution excluded certificants who primarily serve adolescents and/or adults. The BACB sent out an email invitation with the link to the survey in January 2020, and sent a follow-up reminder email 2 weeks later. In addition, invitations to participate in the study were advertised in large Facebook groups geared toward behavior analytic professionals.

Survey design

The survey was designed by the authors in REDCap, a database designed for secure electronic data capture (Harris et al., 2009), and reviewed by five experts in the area of behavior analysis and/or NDBIs. The items, practices, and interventions represented in the survey were selected from the three seminal publications in the field (Table 1; Bruinsma et al., 2019; Frost et al., 2020; Schreibman et al., 2015). Ten researchers who have published peer-reviewed studies of NDBIs were invited to evaluate the survey, and five researchers provided feedback about wording, definitions, and strategies addressed. The design team did not include autism community members or stakeholders. The survey was revised to improve clarity and to ensure that a representative sample of NDBI practices, strategies, and readings were incorporated into the survey. The email invitation, with university Internal Review Board approved language, indicated that respondents would be eligible to win one of ten available US$50 gift cards to an online retailer if they provided their email following survey completion. Those who provided an email were entered into a random number generator to select ten respondents to receive the gift card 1 month following the survey closure. The first page of the survey provided a consent statement.

Table 1.

NDBI strategies.

Strategy	Source
Strategy	Bruinsma et al. (2019)	Frost et al. (2020)	Schreibman et al. (2015)
Responding to child attempts to communicate	X	X	X
Reciprocal turn taking	X	X	X
Language expansions	X
Language extensions	X
Recasting	X	X
Building play routines with predictable steps	X	X	X
Modeling positive affect and animation	X	X	X
Play expansions	X	X	X
Language modeling	X	X	X
Joint attention modeling	X	X	X
Modeling and expanding symbolic play	X	X	X
Increasing parent sensitivity to child communicative attempts	X	X	X
Following the child’s lead	X	X	X
Selecting goals and targets from a typical developmental sequence	X	X	X
Teaching in home routines	X		X
Building predictable social routines	X	X	X
Teaching in play routines	X	X	X
Arranging the environment to increase communication opportunities	X	X	X
Playful obstruction or sabotage	X	X	X
Expectant waiting	X	X	X
Natural reinforcement (providing the next piece of a toy or material)	X	X	X
Time delays	X	X	X
Using typical developmental sequences to inform intervention targets	X		X
Broadening the attentional focus of the child	X		X
Modeling play in the child’s attentional focus			X
Mapping	X
Imitation of play or language	X		X
Using embedded communication temptations	X	X	X
Using embedded direct teaching episodes	X	X	X
Child initiated teach episodes	X	X	X

The survey consisted of seven subsequent forms with responsive items that allowed for additional items to be generated depending on respondents’ answers to certification questions. To simplify data processing and analysis of results, most survey questions asked respondents to endorse one or more of the options presented, rather than generate individual responses. The seven forms were designed to collect information on the following areas: (1) the respondent’s demographic and certification level information, (2) the respondent’s clientele and service delivery, (3) the respondent’s knowledge about NDBIs, (4) the respondent’s familiarity with NDBI interventions, (5) the respondent’s use of NDBI practices, (6) the respondent’s beliefs about effective interventions available for different areas of development, and (7) the respondent’s training in NDBI practices.

Demographics

Demographic survey questions probed age range, gender, race, ethnicity, location, education level, and BACB certification. Respondents indicated which BACB certification they currently held (as well as other dual certifications), the approximate length of time they had held it, and whether they were actively serving clients or on short- or long-term leave.

Clientele and service delivery

Survey questions regarding clientele asked respondents to indicate the primary age range and diagnosis of the majority of clients they serve, as well as the percentage of clients with goals specific to language, communication, or speech development. In regard to service delivery, survey questions probed the most common service delivery setting, range of total hours per week that services were typically provided to a client, and the extent to which services featured DTT, naturalistic interventions, positive behavior support, and parent training.

Knowledge about NDBIs

Open-ended questions were used to examine respondent knowledge of NDBIs. Respondents were asked to indicate whether or not they were familiar with the NDBI term. Those who indicated familiarity were then asked to briefly describe NDBIs in one sentence, and subsequently to give an example of either an NDBI or an NDBI strategy.

Familiarity with NDBIs

All respondents, including those who did not indicate familiarity with the NDBI term, were then presented with a series of named interventions and curricula and asked to indicate whether they (1) were unfamiliar, (2) were familiar, (3) have used, (4) have formal training in, and/or (5) bill for. Named interventions included traditional behavioral interventions, NDBIs, and those that are not associated with either of the aforementioned intervention categories, and were the following: Early Start Denver Model (ESDM), ImPACT (Improving Parents as Communication Teachers), Enhanced Milieu Teaching (EMT), Pivotal Response Training (PRT), DTT, Floor time, Picture Exchange Communication System (PECS), Social Communication, Emotional Regulation, and Transactional Support (SCERTS), Sensory-based interventions (e.g. swinging, brushing, weighted vests, and joint compressions), Dialogic Reading, TEACCH, music therapy, Joint Attention, Structured Play, Engagement Regulation (JASPER), Incidental Teaching, VB-MAPP curriculum, NET, Building Blocks, and Prelinguistic Milieu Teaching.

Use of NDBI practices

To gauge professional use of NDBI practices, respondents were presented with a series of strategies shared among NDBIs and asked to endorse whether they either (1) were unfamiliar, (2) were familiar with the strategy but did not use, (3) used the strategy rarely (i.e. 5%–15% of the time), (4) used the strategy somewhat (i.e. 16%–50% of the time), (5) used the strategy most of the time (i.e. 50%–90% of the time), or (6) used the strategy almost all of the time (i.e. >90% of the time). The strategies included in this series and the relevant references are outlined in Table 1.

Beliefs about effective interventions

For each of a series of developmental areas, we asked survey respondents to endorse which, if any, of the following interventions they believed to be effective for improving outcomes in that area: (1) NDBIs, (2) DTT, (3) PECS, (4) EIBI, (5) Incidental Teaching, and (6) parent training. Respondents were able to select which, if any, practices they believe are effective for improving each of the developmental areas, and responses were not required for any particular area. The developmental areas presented were the following: social communication, play skills, challenging behavior, play development, joint attention skills, receptive language, symbolic play, eye contact, imitation skills, turn taking, self-care skills, gestures, disruptive behaviors, social skills, repetitive behaviors, language skills, and joint engagement. Respondents were then asked to rate as true or false their agreement with statements endorsing that BCBAs should be familiar with early developmental sequences, and endorsing NDBIs as important tools for behavioral professionals working with young children on the autism spectrum or those with developmental delays, as effective strategies for improving social communication and broader development in this population, or as effective strategies that should be used by other professionals but outside the scope of practice of behavioral professionals.

Training in NDBI practices

Finally, survey respondents were asked to endorse whether they had (1) never, (2) once, or (3) more than once been exposed to any of a series of NDBI training experiences through either a BCBA supervisor or an instructor/professor. This series included specific NDBI-focused reading assignments (Dawson et al., 2010; Schreibman et al., 2015), observation of an NDBI intervention session, observation of parent training of NDBI strategies, instruction on the developmental sequence of play, instruction on the developmental sequence of language, instruction on the developmental sequence of speech sounds, and instruction on the developmental sequence of social communication. Similarly, respondents who indicated they were instructors of BACB-approved courses or supervisors responded to similar questions gauging whether they had either (1) never, (2) once, or (3) more than once provided such training experiences to their students or supervisees.

Participants

A total of 995 surveys were initiated and 901 surveys were submitted with sufficient data for analysis. The sample was mostly female (88%), white (74%), non-Hispanic/Latinx (83%), and practicing in the United States (92%; the sample reflects current demographics across the BACB; BACB Certificant Data, n.d.). Although all respondents reported working with young children on the autism spectrum and/or developmental disabilities, most respondents specifically reported that the majority of the children they serve are younger than 8 years old (75%), and have autism (60%), or autism and developmental disabilities (31%). Respondents were just as likely to serve clients in a clinic (37%) as at home (36%), and reported total weekly hours of intervention ranging widely from 2 to 20 h per week (Table 2).

Table 2.

Demographics.

%	BCBA-D	BCBA	BCaBA	RBT	Total
N	29	408	32	432	901
Years held certification
<1 year	3%	15%	40%	40%	28%
1–3 years	3%	25%	22%	48%	35%
3–5 years	7%	19%	9%	9%	14%
5–10 years	38%	27%	25%	3%	16%
10+ years	48%	13%	3%	0.5%	8%
Highest degree
Doctoral degree	100%	4%	0%	< 1%	5%
Master’s degree	–	96%	40%	20%	56%
Bachelor’s degree	–	–	60%	56%	29%
Some college/associate’s degree	–	–	–	22%	9%
High school	–	–	–	1%	1%
Primary area of study
Behavior analysis	34%	60%	44%	22%	40%
Special education/early intervention	21%	18%	13%	13%	16%
Psychology	34%	13%	28%	53%	33%
Other	11%	9%	15%	12%	12%
Age range
<30 years old	3%	19%	26%	69%	43%
30–40	41%	49%	45%	19%	34%
>40	55%	31%	28%	12%	22%
Gender
Female	83%	90%	90%	88%	89%
Male	17%	10%	6%	11%	10%
Prefer not to say	0%	0%	3%	1%	0.5%
Non-binary	0%	0.25%	0%	0.3%	0.2%
Transgender	0%	0%	0%	0.3%	0.1%
Race
White	90%	85%	78%	66%	76%
Black	7%	2%	6%	11%	7%
Asian/Native Hawaiian/Pacific Islander	0%	9%	6%	11%	10%
Other	3%	4%	9%	13%	7%
Ethnicity
Hispanic/Latinx	7%	9%	16%	23%	16%
Location
Canada	0%	4%	0%	1%	2%
Mexico/South America	0%	0.3%	0%	0%	0.2%
Asia/Middle East	0%	3%	6%	2%	3%
Africa	0%	0%	0%	0.3%	0.1%
Europe/the United Kingdom	0%	3%	3%	1%	2%
The United States^a	100%	90%	90%	95%	93%
West	17%	17%	18%	20%	19%
Southwest	24%	17%	7%	22%	20%
Southeast	28%	22%	36%	29%	26%
Midwest	7%	18%	25%	15%	16%
Northeast	24%	25%	11%	12%	18%
Alaska/Hawaii	0%	1%	4%	2%	0.3%
Location where clients are primarily served
In home	52%	39%	34%	41%	40%
In clinic	38%	36%	47%	44%	40%
In schools	10%	25%	19%	16%	20%
Hours per week served average client
<5 h	54%	49%	15%	10%	29%
5–10 h	14%	15%	41%	26%	21%
10–20 h	21%	15%	12%	28%	21%
>20 h	11%	21%	31%	37%	28%
Primary age of clients served
0–5	41%	41%	41%	46%	43%
5–8	45%	39%	28%	38%	39%
>8	13%	19%	31%	15%	17%
Primary diagnosis served
Autism	48%	63%	69%	69%	65%
Developmental disabilities	0%	1%	0%	1%	1%
Autism and developmental disabilities	48%	35%	30%	30%	32%
Typical	3%	0%	0%	0.5%	0.2%
Delivers DTT to clients >25% of the time	28%	46%	63%	65%	56%
Delivers naturalistic interventions to clients >25% of the time	86%	77%	81%	84%	81%
Delivers parent training	97%	95%	99%	75%	26%
Serves clients with language/communication goals	100%	99%	100%	100%	99%

BCBA-D: Board Certified Behavior Analysts with doctoral distinction; BCBA: Board Certified Behavior Analyst; BCaBA: Board Certified Assistant Behavior Analyst; RBT: Registered Behavior Technician; DTT: discrete trial teaching.

US regions are percent of applicants living in the Unites States. Response rates >99% across demographics.

Analysis

Respondents who did not identify current BACB certification, or who did not complete at least 25% of the survey questions, were removed from the analyses. All other survey responses were retained. Responses were analyzed using descriptive statistics. All analyses were conducted based on complete responses, and missing data were excluded. Where appropriate, all results include the number of respondents who answered the given item. Chi-square analyses were used to estimate the association between certificant characteristics (i.e. training type or client age) and NDBI knowledge/training. Free-response answers were reviewed independently by both authors and rated for correctness and intervention features. These qualitative results were analyzed by theme.

Results

Response rate

The survey was advertised in Facebook groups geared toward behavioral professionals, and distributed to 37,329 BACB certificants initially with a bounce rate of 0.2%, open rate of 25%, and a click through rate of 8.6%. During the follow-up email distribution, 37,162 total recipients were sent the email, with a 0.2% bounce rate, 18% open rate, and 5.3% click through rate. Thus, there were 1295 total click throughs to access our survey, resulting in approximately 70% completion rate for those who clicked through. Furthermore, completed surveys represent 2.5% of the BACB certificants reached by this email solicitation. Click through rates for Facebook groups are unknown; however, a few responses were logged immediately following the Facebook post.

Type of intervention delivery

Supervising BACB professionals (BCBA, BCBA-D, or BCaBAs) reported providing services for an average of 2.9–3.9 h (standard deviation (SD) = 1.6–1.8) per week per client, while RBTs reported an average of 4.4 h (SD = 1.5) providing services per client per week. Most professionals reported providing both DTT and naturalistic interventions to their clients (Table 2). Almost all professionals reported serving clients with social communication goals (>99%). Most supervising professionals reported training parents (>95%), and as many as 75% of RBTs reported training parents.

Knowledge about and use of NDBIs and related strategies

Eleven percent of responding supervising professionals and 25% of responding RBTs were reportedly unfamiliar with all of the named NDBIs, and 38% of supervising professionals and 36% of RBTs recognized fewer than three named NDBIs. In contrast, 62% of supervising professionals and 47% of RBTs reported implementing at least one NDBI into practice regularly with clients. Yet, many respondents (32% of supervising professionals and 46% of RBTs) reported that they had not received formal training in any NDBI practice. Interestingly, a similar pattern of familiarity was observed across common direct teaching practice (including DTT, TEACCH, PECS, or following the VB-MAPP curriculum).

Reported use of specific NDBI strategies varied greatly. The strategies most frequently reported as unfamiliar or unused by behavioral professionals were language expansions/extensions or recasting (RBT = 22%; supervising professionals = 23%), play expansions (RBT = 37%, supervising professionals = 33%), modeling and expansion of symbolic play (RBT = 36%, supervising professionals = 20%), and broadening the attentional focus of the child (RBT = 25%, supervising professionals = 23%). A substantial percentage of RBTs also reported they were not familiar with or did not use strategies such as modeling joint attention (28%), or increasing parent sensitivity to child communication (40%). The strategies reportedly incorporated most of the time by the most professionals were responding to child communication attempts/reciprocal turn taking (RBT = 82%, supervising professionals = 91%), language modeling and mapping (RBT = 70%, supervising professionals = 79%), and incidental teaching techniques (i.e. time delay, embedded prompting, and child initiated; RBT = 65%, supervising professionals = 80%). Detailed results regarding professional use of specific NDBI strategies are reported in Table 3.

Table 3.

NDBI familiarity.

%
Familiar with term NDBI
BCBA(-D); BCaBA (n = 469)	21%
RBT (n = 432)	12%
	None	1–2	3–4	>5
Familiar with behavior analytic named practices
BCBA(-D); BCaBA (n = 469)	29%	42%	17%	12%
RBT (n = 432)	37%	41%	16%	4%
Use behavior analytic named practices
BCBA(-D); BCaBA (n = 469)	24%	17%	53%	6%
RBT (n = 432)	32%	28%	39%	<1%
Formal training in behavior analytic named practices
BCBA(-D); BCaBA (n = 469)	32%	24%	40%	3%
RBT (n = 432)	46%	28%	25%	<1%
Familiar with NDBI named practices
BCBA(-D); BCaBA (n = 469)	11%	38%	34%	16%
RBT (n = 432)	25%	36%	25%	13%
Use NDBI named practices
BCBA(-D); BCaBA (n = 469)	21%	62%	15%	2%
RBT (n = 432)	34%	47%	15%	2%
Formal training in NDBI named practices
BCBA(-D); BCaBA (n = 469)	32%	24%	40%	3%
RBT (n = 432)	46%	29%	25%	<1%
NDBI strategies	Unfamiliar	Familiar, do not use	Rare/somewhat	Most/always
Responding to child communication attempts/reciprocal turn taking
BCBA(-D); BCaBA (n = 399)	2%	2%	5%	91%
RBT (n = 363)	2.2%	<1%	15%	82%
Language expansions/extensions or recasting
BCBA(-D); BCaBA (n = 383)	17%	5%	15%	63%
RBT (n = 357)	15%	7%	23%	55%
Building play/social routines with predictable steps
BCBA(-D); BCaBA (n = 400)	4%	4%	33%	69%
RBT (n = 359)	5%	5%	34%	55%
Modeling positive affect and animation
BCBA(-D); BCaBA (n = 402)	10%	6%	21%	62%
RBT (n = 363)	11%	7%	23%	57%
Play expansions
BCBA(-D); BCaBA (n = 398)	26%	7%	23%	45%
RBT (n = 359)	29%	8%	28%	34%
Language modeling/mapping
BCBA(-D); BCaBA (n = 398)	5%	3%	12%	79%
RBT (n = 365)	5%	5%	20%	70%
Joint attention modeling
BCBA(-D); BCaBA (n = 402)	7%	6%	23%	64%
RBT (n = 365)	18%	10%	27%	46%
Modeling and expanding symbolic play
BCBA(-D); BCaBA (n = 393)	12%	8%	32%	49%
RBT (n = 351)	15%	11%	31%	42%
Increasing parent sensitivity to child communication
BCBA(-D); BCaBA (n = 396)	7%	8%	28%	57%
RBT (n = 361)	19%	21%	32%	28%
NDBI strategies	Unfamiliar	Familiar, do not use	Rare/somewhat	Most/always
Following the child’s lead
BCBA(-D); BCaBA (n = 399)	2%	4%	31%	62%
RBT (n = 359)	4%	3%	39%	54%
Goals and targets selected from typical developmental sequence
BCBA(-D); BCaBA (n = 388)	2%	3%	18%	77%
RBT (n = 351)	7%	7%	27%	60%
Teaching in home or play routines
BCBA(-D); BCaBA (n = 391)	3%	4%	24%	68%
RBT (n = 361)	3%	3%	36%	59%
Broadening attentional focus of the child
BCBA(-D); BCaBA (n = 394)	17%	6%	28%	49%
RBT (n = 359)	14%	11%	35%	40%
Imitation of play or language
BCBA(-D); BCaBA (n = 396)	3%	3%	23%	71%
RBT (n = 361)	3%	4%	31%	62%
Incidental teaching techniques (time delay, embedded prompting, and child initiated)
BCBA(-D); BCaBA (n = 384)	2%	1%	15%	80%
RBT (n = 349)	3%	1%	30%	65%

NDBI: Naturalistic Developmental Behavior Interventions; BCBA-D: Board Certified Behavior Analyst with doctoral distinction; BCaBA: Board Certified Assistant Behavior Analyst; RBT: Registered Behavior Technician.

Supervisory professionals were more likely to be familiar with NDBIs compared to RBTs (χ² = 10.37, p = 0.001), and more likely to have received formal training in any of the named NDBIs (χ² = 6.65, p = 0.006). However, professionals who reported primarily working with children under the age of 5 years were no more likely to be familiar with NDBIs (χ² = 0.71, p = 0.399) or have formal training (χ² = 1.03, p = 0.309) compared to those who worked primarily with older children. In addition, professionals’ educational backgrounds (special education/early intervention vs psychology/ABA/other) were unrelated to NDBI familiarity (χ² = 1.12, p = 0.291) or training (χ² = 0.00, p = 1).

Beliefs about NDBIs in early intervention

Many survey respondents believe that NDBIs are important for improving social communication (RBTs = 33%; supervisors = 38%), play development (RBTs = 32%, supervisors = 38%), receptive language (RBTs = 27%, supervisors= 34%), and joint engagement (RBT = 31%, supervisors = 37%). Only 64% of RBTs and 57% of supervisors believe that NDBIs are an important tool for BACB professionals. A similar rate of professionals reported that NDBIs are an important and effective tool for improving social communication outcomes for children with autism (RBTs = 64%; supervisors = 56%).

Training in NDBIs

A total of 136 supervising professionals and 277 RBTs answered questions regarding NDBI training experiences. More than 75% of BACB professionals have never been assigned to read the primary article defining NDBI practices (Schreibman et al., 2015), or one of the most commonly cited studies of NDBI practices (Dawson et al., 2010). Yet, 29% of BACB supervising professionals have assigned one of the seminal readings to supervisees and/or students (Dawson et al., 2010; Schreibman et al., 2015). A few RBTs reported having ever observed an NDBI session (48%), and even fewer supervising professionals (29%) reported the same. Only 44% of supervisors and 45% of RBTs have received consistent training in developmental sequences. As many as 93% of supervising professionals and 90% of RBTs indicated interest in participating in formal NDBI training.

Description of NDBIs

Only 142 respondents (15%) supplied text responses when asked to define the term NDBI and provide an example. The responses were read and rated by both of the authors for correctness of each and coded for reference to distinguishing features of NDBIs. Coded NDBI features included description or inclusion of the following terms: face-to-face, following the child’s lead, positive affect and animation, modeling appropriate language, using communicative temptations, frequency of direct teaching episodes, quality of direct teaching episodes, contingent imitation, or developmental sequence (Frost et al., 2020). Agreement between raters was strong (range = 90%–100% point-by-point agreement) across items. Disagreements were discussed and a consensus was reached.

Of the 142 responses, 80 respondents (56%) provided a correct example of a named NDBI intervention; however, only 31 (22%) of respondents included at least one distinguishing feature of NDBIs in the definition. Respondents provided detailed definitions which were frequently rated by the authors as more fitting descriptions of NET than NDBI. This was due to frequent reference to use of DTT procedures in the natural environment.

Several themes emerged in our qualitative review of the definitions and general responses provided. First, of the few respondents who considered themselves familiar enough with NDBIs to supply a definition and example, many believed any intervention that is delivered in a natural setting or that leverages natural contingencies qualifies as an NDBI. Thus, behavior professionals appear to understand that NDBIs have a focus on the natural environment, but do not fully grasp the developmental perspective and the teaching procedures used. Second, some professionals believed either that NDBIs were not effective interventions for children on the autism spectrum, or that other interventions were simply more effective. Third, some expressed concern that provision of NDBIs would be outside the behavioral professional’s scope of practice. Finally, some behavioral professionals expressed a desire to integrate NDBIs in their practice, but a frustration at a lack of available training opportunities. Table 4 presents quotes that are emblematic of these themes.

Table 4.

NDBI definition themes.

Beliefs	Representative quotes
NDBIs are interventions offered in the natural environment	Working with clients in the natural environment where the target behavior is often exhibited . . . [i.e.] teaching a child to point to the refrigerator to ask for juice. I have heard NDBI also called NET. Naturalistic Environment Teaching. NDBI supports the learning of clients within their natural environment and opportunities to learn. Behavioral intervention that take place in the individual’s natural environment.
NDBIs include naturally occurring consequences	Interventions in natural environment using naturally occurring stimuli and reinforcement contingencies. Use of naturalistic teaching strategies in variety of settings with family and team members to target a skill/skills with potential reinforcers that are naturally occurring. Using naturally occurring opportunities and reinforcement to teach skills in natural settings.
NDBIs are those embedded in everyday routines	Naturalistic style teaching throughout the day to help generalize skills across environments, [i.e.] Teaching social skills and making the social interaction reinforcing after pairing with established reinforcer. Using natural daily experiences as opportunities for a form of learning . . . [i.e.] mealtimes. When using NDBI we target skills in the naturally occurring routines throughout the clients day.
NDBIs are not in the BACB scope of practice	Conceptually flawed in relation to radical behavior analytic position. BCBAs can pretty effectively work on play and communication skills through discrete trials and naturalistic teaching opportunities. Many of the NDBIs listed on the previous page fall outside of the BCBA’s scope of practice, and many of them have (or include components that have) little to no scientific backing. Additionally, treatment packages further remove the BCBA from the actual science of behavior analysis, such that the intervention becomes more about using the NDBI properly and less about the behavior itself.
Other methods are more effective than NDBIs	Some skills are more efficiently taught and learned thru DTT methods. While I think they are somewhat effective and an easy way to train and get parents on board. Nothing beats fulltime EIBI. That gets better results.
Little or poor training available to BCBAs to learn NDBIs	Most BCBAs have little knowledge of typical child development and even less experience in implementing developmentally appropriate programming. Not taught in course sequence so most aspiring BCBAs are unfamiliar. Should be using regularly but BCBA training programs also need to include info on typical development.

NDBI: Naturalistic Developmental Behavior Interventions; NET: Natural Environment Teaching; BACB: Behavior Analyst Certification Board; BCBA: Board Certified Behavior Analyst; DTT: discrete trial teaching; EIBI: early intensive behavioral intervention.

Discussion

A few behavior professionals recognize or understand what NDBIs are in practice. It is also clear that some BACB professionals’ value NDBI intervention practices, use NDBI intervention practices, and desire more training in NDBI practices. However, a few respondents indicated they had received formal training in any named NDBI interventions or the seminal readings. Furthermore, very few respondents were able to accurately describe NDBI practices and several questioned whether NDBI practices fall within the BACB scope of practice, despite growing evidence that NDBI intervention practices are a particularly effective intervention tool for supporting social communication development in young children on the autism spectrum and those who have related developmental delays (Crank et al., 2021; Tiede & Walton, 2019), the primary population served by behavioral professionals.

Even though the vast majority of respondents reported working on social communication goals with young children, less than half of respondents had received any formal training in relevant developmental sequences. Although the need for greater training is necessary across all behavior professionals, it is important to note that supervisors (i.e. BCBA(-D)s and BCaBAs) were more likely to be familiar with and have training in NDBI practices as compared to RBTs. This highlights the need to increase NDBI training into the RBT basic course and in direct supervision. Thus, supervisors should be trained not only in NDBI practices, but also in procedures for facilitating training of RBTs in practice. Although NDBIs are often developed in and shared widely within the special education field, this does not necessarily increase training or knowledge of professionals from these disciplines. Therefore, training of BCBA professionals and other related autism professionals across all disciplines demonstrate a need for increased education and training in NDBI practices.

Limitations

The results of this study should be cautiously interpreted in light of a few limitations. First, many respondents failed to answer some of the questions toward the end of the survey, potentially introducing some bias in the interpretation of those results. Second, this survey study only included professionals certified by the BACB. While this profession has made many unique contributions to autism intervention practices, there are other intervention professionals who also support social communication and developmental outcomes, namely, speech language pathologists, who could also contribute to our understanding of the training and implementation of NDBI practices for young children on the autism spectrum. Third, the research team did not include members from the autism community or key stakeholders, and future replications should include advocates, parents, and key policy representatives. Finally, respondents were overwhelmingly white, female, located in the United States, and did not identify as Hispanic or Latinx, reflecting a broader lack of racial, ethnic, gender, and regional diversity among BACB professionals (BACB Certificant Data, n.d.). Notably, we observed greater representation of racial and ethnic minorities among entry-level RBT positions relative to other categories of professionals, which may indicate that racial and ethnic minorities encounter systemic barriers to accessing further professional training and career advancement within the field. This highlights the urgent need for BACB training programs to make concerted efforts to recruit and retain more diverse cohorts of students that better reflect the racial and ethnic composition of their respective locale.

Implications for future research

Further understanding of the knowledge and beliefs of NDBI practices is needed to form a robust hypothesis about training needs and future directions for the field. A broader survey could address when and under what circumstances behavior professionals are likely to use NDBI strategies, how many hours behavior professionals use each type of practice, and which students (by diagnosis/age) are most likely to receive NDBIs. The field could also benefit from understanding the barriers to teaching behavior professionals NDBI strategies, and a survey of instructors in this area could be especially informative. Finally, a replication of this study with other key interventionists for children on the autism spectrum (i.e. speech language pathologists, special education teachers, early intervention providers, and paraprofessionals) could help us better understand under who and when these practices are most likely to occur.

Implications and recommendations for training programs and continuing education

It is clear that additional resources and trainings are needed to improve NDBI knowledge and implementation for behavior professionals. We recommend that university level training programs and instructors in certification courses cover early social communication develop-ment sequences, the behavioral principles that inform NDBIs, and key readings that provide an overview of the shared features of NDBIs (particularly those that distinguish them from NET) and their supporting evidence base (Table 5). Instructors and supervisors should also provide specific instruction strategies to supervisory professionals during training, so that these professionals can not only implement NDBIs in their own practice but also effectively teach parents and RBT professionals. In addition, there is a need for training on NDBI practices to be available as continuing education credits. NDBI trainings should be affordable and accessible to all behavior professionals.

Table 5.

Resources for instructors and supervisors.

Conceptual	Resource
Seminal paper authored by the creators of several named interventions featured in the category. Defines key terms and features	Schreibman et al. (2015)
Textbook detailing a conceptual overview, core concepts and foundational principles, and NDBI strategies	Bruinsma et al. (2019)
Meta-analytic support
Meta-analysis demonstrating the effects of NDBIs for improving core and related symptoms of autism compared to other treatment models	Sandbank, Bottema-Beutel, & Woynaroski (2020)
Meta-analysis exploring the effects of NDBIs and the extent to which they vary by intervention characteristics and study quality	Tiede & Walton (2019)
Representative studies
Early Start Denver Model	Dawson et al. (2010, 2012)
JASPER (Joint Attention, Structured Play, Engagement, Regulation)	Kasari et al. (2006, 2008)
Reciprocal Imitation Training	Ingersoll (2012); Ingersoll & Schreibman (2006)
Project ImPACT (Improving Parents as Communication Teachers)	Ingersoll & Wainer (2013)
SCERTS	Wetherby et al. (2014)
Enhanced Milieu Teaching	Hampton et al. (2021); Kaiser et al. (2000)
Adaptations
Voice output device	Kasari et al. (2014)
Cultural adaptation	Peredo et al. (2018)
Preschool classroom	Chang et al. (2016); Kaale et al. (2012); Lawton & Kasari (2012); Shire et al. (2017)
Elementary classroom	Morgan et al. (2018)
Manuals
Early Start Denver Model	Rogers & Dawson (2020)
ImPACT	Ingersoll & Dvortcsak (2019)
PRT in the classroom	Stahmer et al. (2011)
SCERTS	Prizant et al. (2003)

NDBI: Naturalistic Developmental Behavior Interventions; SCERTS: Social Communication, Emotional Regulation, and Transactional Support; PRT: Pivotal Response Training.

Implications for BACB certification and standards

NDBIs are the set of interventions that have accrued support from the most RCTs as effective for improving social communication, language, play, and cognition of young children on the autism spectrum. NDBIs, by definition, include behavioral techniques such as shaping, prompt fading, reinforcement, manipulation of antecedents, and ongoing analytic monitoring of progress. Thus, NDBIs fit squarely within the scope of practice for BACB certificants, despite their low rates of reported familiarity or training in these strategies. We recommend that the BACB consider adding task list items that specifically incorporate NDBI strategies and techniques. Training in this core area is necessary, especially for the over 75% of certificants who work directly with children on the autism spectrum. One alternative is to provide a subspecialty set of task list items such that only those who sub-specialize in autism intervention would be held to standards of NDBI implementation.

Conclusion

While the evidence base is ever changing, certification boards and related instructors must be vigilant in maintaining a high level of standard to keep up. The field of ABA is often criticized for being limited in scope and ridged; by adopting current evidence-based practices into the scope of practice, the field has the opportunity to demonstrate greater flexibility, responsiveness, and evolution. BCBAs are one of the fastest growing fields in early intervention and autism intervention, and because of this, it is imperative that certification programs provide university level training, continuing education, and certification standards toward implementation, training, and supervision of NDBIs.

Footnotes

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) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This study was funded by the University of Texas at Austin Vice President for Research Office.

ORCID iD

Lauren H Hampton

Notes

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