Teaching Multi-step Requesting and Social Communication to Five Autistic Children Using Speech-Generating Devices and Systematic Instruction

Participants

The five participating children were recruited from a university database because they had an autism diagnosis, did not currently use an SGD for multi-step communication, and had sufficient motor control to select icons from the screen of an iPad®-based SGD. All of the participants were considered to be candidates for SGD use because they either had no speech or spoke only a few single words. They were assigned pseudonyms for this report. To confirm their status as minimally verbal, receptive and expressive communication abilities were assessed using the third edition of the Vineland Adaptive Behavior Scales (Vineland-III, Sparrow et al., 2016).

Sean was an 8-year-old male of Russian ethnicity. On the Vineland, he obtained age equivalencies of 1:2 (years:months) and 0:9 for receptive and expressive communication, respectively. He had a history of biting and elopement. At home, he reportedly used an iPad®-based SGD with ProloQuo2Go™ software to make one-step requests for preferred objects.

Chris was a 10-year-old male of Fijian/Indian ethnicity. His receptive and expressive age equivalencies were both 1:7. He had no prior experience with SGDs, but had some experience in using a picture-exchange communication system. Prior to baseline of the present study, he was taught to make one-step requests for preferred objects with an SGD.

Andy was a 6-year-old male of Māori/New Zealand European ethnicity. His receptive and expressive age equivalencies were 0:8 and 0:7 respectively. He had occasional tantrums and some prior experience using an SGD to make one-step requests for preferred objects.

Victor was a 7-year-old male of New Zealand European ethnicity. His receptive and expressive age equivalencies were 0:11 and 0:8 respectively. He occasionally spoke single words (e.g., no, hello, and okay). He had some experience using a SGD to request preferred objects, following a visual schedule, and using a picture-exchange communication system.

Grace was a 7-year-old female of Māori and British ethnicity. Her age equivalencies were assessed at less than 1 month for receptive communication and 0:9 for expressive communication. She used one manual sign (MORE) and also exchanged picture cards to request preferred stimuli (e.g., snacks and television) and to indicate the need to use the toilet. Grace also had experience making simple, one-step requests using her iPad® with ProloQuo2Go™ software.

Procedures

Participants received 1:1 sessions in a quiet private room at their respective schools. During sessions, the child sat at a table/desk with the interventionist (first author). The SGD was placed on the table/desk within the child’s reach. Reinforcers were kept in a clear storage box. A teacher, teacher’s aide, and/or university graduate student was also often in the room during sessions to collect inter-observer agreement and procedural integrity data and serve as the novel interventionist for the generalization probes. Some sessions were video recorded for checking inter-observer and procedural integrity when a live observer was not available.

Preferred Stimuli

Preferred stimuli that the participants would be taught to request were identified using a two-stage stimulus assessment process (Fisher et al., 1996). Stage 1 involved asking parents and teachers to provide a list of snacks and toys that the children seemed to enjoy. During stage 2, four items from each list were used in a paired stimulus preference assessment procedure. Specifically, a pair of items from each category (e.g., toys or snacks) were presented and the child was asked to choose one item. Every item was paired with every other item of the same category (toys or snacks), and the process was repeated a minimum of four times. When a snack item was selected, the child was allowed to consume a bite-sized portion of that item. When a toy was selected, the child was allowed to play with the toy for 30 s. Each child’s two most frequently selected snacks and toys were retained for use in the study (see Table 1). Note that because of dietary concerns, Grace’s preferred snacks were identified by her mother and not from the stage 2 procedure.

Table 1 Preferred stimuli identified for each participantSpeech-Generating Device

Children were taught to engage in a four-step requesting and social communication sequence by selecting icons from an iPad® that was loaded with Proloquo2Go™ software (Sennott & Bowker, 2009). Each iPad® was configured with four progressive screens with each screen containing two icons. The two icons on screen 1 were HELLO and THANK YOU. Activating the HELLO icon produced corresponding synthesized speech output (“Hello”) and then also automatically progressed to screen 2. In contrast, activating the THANK YOU on screen 1 generated relevant speech output (“Thank you”), but did not progress to the next screen as this was an incorrect response at step 1. The next screen (screen 2) contained two icons (SNACK and TOY) representing general requests for a snack or a toy. Selecting an icon on screen 2 produced corresponding speech output (i.e., “I want a snack” or “I want a toy”). Also, as soon as the icon was selected, the next page (screen 3) appeared. On screen 3, participants could make a more specific request for one of their two preferred snacks or for one of their two preferred toys depending on whether they had selected the SNACK or TOY icon on the previous page (screen 2). After making a specific request from screen 3, the display progressed to screen 4 which contained the HELLO and THANK YOU icons again. Activating either icon did not take the user to another screen, but only generated corresponding speech output (i.e., “Hello” or “Thank you”). The icons used on screens 1, 2, and 4 were SymbolStix™ images taken from the Proloquo2Go™ database and these were identical for all five participants. The snack and toy icons appearing on screen 3, in contrast, were individualized for each participant, based on the results of the prior preference assessment. Individualized icons for screen 3 consisted of photographs of their two preferred snacks or their two preferred toys. All of the synthesized speech output was in a standard English/Australian accent in a boy’s voice for Sean, Chris, Andy, and Victor or in a girl’s voice for Grace.

Response Definition and Measurement

Correct responding was defined as independently activating (i.e., without prompting) the correct icon so as to generate speech output at each step in the communication sequence. First, at the start of each communication opportunity, the participant had to greet the researcher by selecting the HELLO icon within 10 s of the interventionist initiating an opportunity. The interventionist initiated an opportunity by looking at the participant and saying Hello. Let me know if you want a snack or a toy. The second step required the participant to make a general request for a toy or a snack by selecting the SNACK or the TOY icon from screen 2. Again, this response had to occur within 10 s of that screen appearing on the SGD. For the third step of the communication sequence, the participant had to make a specific request by selecting one of the two specific snack or toy icons that were available on screen 3 within 10 s of that screen appearing. Lastly, the participant had to select the THANK YOU icon from screen 4 within 10 s of that screen appearing.

Data on performance at each step were collected for each communication opportunity initiated by the interventionist. If a participant did not activate an icon within 10 s of a screen appearing, a non-response was recorded. An incorrect response was recorded if the participant selected an icon that was incorrect for that step. In the four-step sequence, errors could occur on screen 1 by selecting the THANK YOU icon rather than the HELLO icon and on screen 4 by selecting the HELLO icon rather than the THANK YOU icon.

Experimental Design and Sessions

Intervention effects were evaluated in a multiple-baseline across participants design (Kennedy, 2005). The design included the following sequence of experimental phases: (a) baseline, (b) intervention, and (c) follow-up. Generalization probes, which involved having a second person serve as the interventionist, were conducted during each phase of the study. One such probe occurred for each participant in baseline and follow-up and three generalization probes occurred during intervention.

Sessions were scheduled to occur at the same time of the day for each participant, 2 days per week (Tuesday and Thursday), barring absences and school holidays. Baseline and follow-up sessions were approximately 15 min in duration and consisted of four communication opportunities. Intervention sessions of about 15 min duration also consisted of four communication opportunities, but each intervention session was proceeded by a set of four practice runs. During practice runs, participants were physically prompted to complete the four-step communication sequence a total of four times in rapid succession. Data on participants’ responses were only collected during the communication opportunities, not during the practice runs.

Baseline

Each of the four communication opportunities during baseline was initiated by the interventionist saying Hello. Let me know if you want a snack or a toy. The box of preferred stimuli and the iPad® were placed on the table with the iPad® in reach and open to screen 1. After initiating an opportunity, the interventionist waited for 10 s and then recorded data on the participant’s responses for each step of the sequence. A correct response at each step (e.g., selecting the HELLO icon from screen 1) was followed by the interventionist making a relevant spoken comment (replying with Hi or Hello). Correct performance of the entire sequence would have resulted in the participant receiving the requested item, but this never occurred in baseline. If an opportunity ended due to non-responding within 10 s or due to an error, the box of preferred stimuli reinforcers was moved out of sight. After an approximate 30-s inter-opportunity interval, the interventionist initiated the next communication opportunity by saying Hello. Let me know if you want a snack or a toy.

Intervention

Immediately prior to each intervention session, four practice runs were conducted. For each practice run, the participant was physically prompted to complete the four-step communication sequence (one practice run for each preferred snack and toy in random order). Practice runs were suspended after the participant correctly participated in the extended communicative exchange with 100% accuracy over three consecutive sessions. Performance during practice runs was not considered in this criteria nor are practice run data presented in Fig. 1 (see “Results”). An intervention session began about 30 s after the last practice run. Each session consisted of four communication opportunities that were initiated as in baseline. Any correct responses were followed by progression to the next screen and by the interventionist making a socially appropriate reply. Also, the requested snack or toy was delivered following the completion of step 4 of the sequence. During intervention sessions, prompting was only used at step 4 if the participant did not independently activate the THANK YOU icon within 10 s of arriving at screen 4. Prompting consisted of holding up the requested item and waiting for 10 s for the final (i.e., THANK YOU) response to occur before delivering the requested item. If the THANK YOU response still did not occur within 10 s of holding up the item, then the child was physically prompted to tap the THANK YOU icon using the least amount of physical guidance necessary. We required participants to select the THANK YOU icon before receiving the requested item because this is consistent with New Zealand social norms and we also reasoned it would be necessary to ensure participants had a reason to complete the final step of the sequence.

Fig. 1figure 1

Percentage of opportunities with correct performance of the communication sequence for each participant and each session

Correspondence Tests

A total of 12 correspondence tests were conducted for each participant. Testing began after the participant had maintained 100% correct performance across three intervention sessions. Each test sought to determine if the participant would select the item that matched their prior request. A test was conducted after the participant had completed the communication sequence, but before the requested item was delivered. Instead of delivering the item, the interventionist presented the box of preferred stimuli and recorded which item the participant selected from the box. For each test, we recorded the icon activated at step 3 and then the real item that the participant selected from the box of preferred items when this box was then offered to them.

Follow-Up and Generalization

Two follow-up sessions were conducted from three to eight weeks after the last intervention session. The procedures were the same as in the intervention phase except that practice runs were not conducted and the final response of selecting the THANK YOU icon was never prompted. Generalization probes were conducted by either a teacher, teaching assistant, or graduate student rather than the interventionist. Generalization probes were conducted in the baseline, intervention, and follow-up phases using the baseline procedures.

Inter-observer Agreement and Procedural Integrity

Agreement checks on data recording by an independent observer (either live or from videotapes) occurred during a minimum of 20% of the sessions in each phase and for each participant. Agreement percentages, calculated using the formula: agreements/(agreements + disagreements) × 100, ranged from 89 to 100. Independent observers also conducted checks on procedural integrity using a checklist to determine if the procedural steps had been implemented correctly. Checks occurred during 22 to 37% of sessions per participant, with a minimum of one observation for each phase of the study. The resulting percentages of correct implementation were always 95% or above.

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