XXX10.1177/1098300712437044Walton and IngersollJournal of Positive Behavior Interventions © 2011 Hammill Institute on Disabilities Reprints and permission: http://www. sagepub.com/journalsPermissions.nav
Evaluation of a Sibling-Mediated Imitation Intervention for Young Children With Autism
Journal of Positive Behavior Interventions 14(4) 241–253 © 2012 Hammill Institute on Disabilities Reprints and permission: sagepub.com/journalsPermissions.nav DOI: 10.1177/1098300712437044 http://jpbi.sagepub.com
Katherine M. Walton, MA1 and Brooke R. Ingersoll, PhD1
Abstract Parents and peers have been successful at implementing interventions targeting social interactions in children with autism; however, few interventions have trained siblings as treatment providers.This study used a multiple-baseline design across six sibling dyads (four children with autism) to evaluate the efficacy of sibling-implemented reciprocal imitation training. All six typically developing siblings were able to learn and use contingent imitation, four of the six siblings were able to learn and use linguistic mapping, and all six siblings increased their use of at least one component of the imitation training procedure. Three of the four children with autism showed increases in overall imitation and all four showed evidence of increases in joint engagement. Parents and siblings reported high satisfaction with the intervention, and ratings by naïve observers indicated significant changes from pre- to posttreatment.These results suggest that sibling-implemented reciprocal imitation training may be a promising intervention for young children with autism. Keywords children with autism, family-based interventions, siblings, imitation
Autism is a pervasive developmental disorder that emerges early in childhood and has profound effects on social functioning and communication (American Psychiatric Association, 2000). Because of the significant social difficulties of children with autism, a large number of interventions for these children have focused on the development of social skills (see McConnell, 2002, for review). Interventions that have focused on teaching social interaction skills in natural settings and have involved social interaction partners with whom the child with autism is most likely to interact, such as parents and peers, have shown the best evidence of generalization and maintenance of these skills (Rogers, 2000). Research indicates that parents (e.g., Drew et al., 2002) and peers (e.g., McGee, Almeida, Sulzer-Azaroff, & Feldman, 1992; Pierce & Schreibman, 1995) can be successfully taught to implement intervention strategies, and these interventions lead to improvement in social communication skills for the children with autism. Much less research, however, has been devoted to training siblings as intervention providers. Involving siblings in social skill interventions for children with autism may be particularly successful as siblings spend a significant amount of time with each other in a variety of situations. Furthermore, siblings’ natural play patterns may provide more opportunities for social interactions and play initiations by the children with autism than those
of parents (El-Ghoroury & Romanczyk, 1999). However, typical siblings also make few attempts to interact with their siblings with autism during free play sessions (El-Ghoroury & Romanczyk, 1999), suggesting that they may benefit from instruction in techniques to facilitate social interaction with their brother or sister with autism. The few studies that have examined sibling-mediated interventions for children with autism indicate that this approach can be successful. For example, siblings have successfully used prompting and reinforcement strategies to increase play behaviors in their siblings with autism (Celiberti & Harris, 1993; Coe, Matson, Craigie, & Gossen, 1991). In a more extensive intervention, typical siblings of children with autism spectrum disorders (ASD) were taught a series of skills in 10 lessons, including staying in physical proximity to the child with ASD, gaining the child’s attention, creating opportunities for social interaction, 1
Michigan State University, East Lansing, MI, USA
Corresponding Author: Katherine M. Walton, Michigan State University, 69F Psychology Building, East Lansing, MI 48824, USA Email: [email protected] Action Editor: Aubyn Stahmer
242
Journal of Positive Behavior Interventions 14(4)
Table 1. Participant Characteristics at Intake Target child
Chronological age
Nonverbal skill levela
Language skill levelb
Ryan Patrick Daniel Chris
3 years 10 months 4 years 9 months
3 years 5 months 2 years 1 months
2 years 6 months >1 year 4 months
4 years 5 months 3 years 9 months
2 years 3 months 2 years 3 months
>1 year 4 months >1 year 4 months
Sibling
Sibling age
Baseline length
Mark Eric Andrea Lily Kristen Melissa
9 years 8 years 9 years 13 years 8 years 10 years
4 weeks 6 weeks 8 weeks 5 weeks 8 weeks 10 weeks
a
Bayley Scales of Infant Development, 3rd Edition, Cognitive Scale. MacArthur-Bates Communicative Development Inventory,Vocabulary Checklist.
b
organizing and negotiating about play ideas, offering and asking for help, asking for clear directions, and providing verbal feedback. The typical siblings were able to effectively use these skills with the child with ASD, leading to increases in social interaction (a targeted skill) and joint attention (a nontargeted skill) in the children with ASD (Tsao & Odom, 2006). Reciprocal imitation, in which partners imitate one another in extended turn-taking sequences, may offer another important treatment target for children with autism and their siblings, because it can facilitate social coordination between peers (Eckerman, Davis, & Didow, 1989). Reciprocal imitation training (RIT) is an intervention designed to increase reciprocal imitation skills in children with autism in a naturalistic social context (Ingersoll, 2008). RIT has been successful at increasing imitation in 2- to 4-year-old children with autism, with generalization to different settings, therapists, and materials, and maintenance over time (Ingersoll, 2010; Ingersoll, Lewis, & Kroman, 2007; Ingersoll & Schreibman, 2006). The intervention also increased joint attention, language, and play skills; these skills are theoretically related to imitation but were not directly targeted in the intervention (Ingersoll & Schreibman, 2006). Mothers of children with autism have also successfully implemented RIT with their children (Ingersoll & Gergans, 2007). This success as a parent-implemented treatment and the simplicity of the intervention suggest that it could be adapted for use as a sibling-implemented intervention. In the present study, we trained typically developing children to implement RIT with their younger brothers with autism. We assessed whether siblings correctly implemented the strategies involved in RIT and examined the effect of the intervention on imitation and joint engagement in the children with autism. We also examined whether skills learned during the course of the intervention generalized to different materials, settings, and typically developing play partners and maintained over time. Furthermore, we examined whether naïve observers were able to detect differences in the sibling interactions from pre- to posttreatment. Finally, we measured the acceptability of the intervention to parents and typically developing siblings.
Methods Participants Four young children with autism and six typically developing siblings participated. Target children were diagnosed by a professional with expertise in autism and exceeded the cutoff scores for “autism spectrum” on the social, communication, and social + communication algorithms of the Autism Diagnostic Observation Schedule–Module 1 (ADOS; Lord et al., 2000). At intake, children were administered the Bayley Scales of Infant Development, 3rd Edition cognitive scale (Bayley, 2006) to estimate nonverbal cognitive skills. Children’s primary caregivers completed the MacArthurBates Communicative Development Inventory (CDI; Fenson et al., 1993) as a measure of vocabulary development. Because the children were older than the norming sample ranges on the Bayley and CDI, age equivalents will be reported instead of standard scores (Table 1). Siblings were between the ages of 8 and 13. In families with more than one child who fell in the target age range, all siblings were invited to participate. In two families, two siblings were interested in participation. For these families, sessions were conducted separately for each sibling, and baseline lengths for the two siblings were staggered by 2 weeks. All siblings were reported to be developing typically, although Mark’s mother reported that he may have some undiagnosed sensory concerns.
Setting and Materials All sessions were conducted in the participants’ homes. One room in the home was chosen based on convenience for the family and for filming, and all sessions were conducted in this room. Seven to eight pairs of duplicate toys were provided by the sibling trainer at the beginning of baseline. Toys were chosen based on parent input, developmental appropriateness for the child with autism, and interest to the typically developing siblings. The children were encouraged to use these toys during the baseline and training sessions; however, they often used other toys that
243
Walton and Ingersoll Table 2. Summary of Behaviors Targeted in Each Treatment Phase Sibling behaviors Treatment phase Phase I Phase II Phase III Phase IV
Contingent imitation
Linguistic mapping
X X X X
X X X
Modeling
Child behaviors Prompting
X X
X
Praise
X X
Joint engagement
Imitation
X X X X
X X
Note. Behaviors marked with an “X” were targeted in the indicated treatment phases.
were accessible in the filming space in addition to these toys.
Procedure A multiple-baseline design was conducted across dyads. The trainer (first author) visited the participants’ homes twice a week throughout baseline and treatment. She was a graduate-level student with approximately 2 years of experience working with young children with ASD. She had been trained in direct implementation of RIT by the second author and had been using RIT for approximately 1 year. Sessions were videotaped for later scoring.
Baseline. During baseline sessions, the sibling was instructed to “Play with your brother like you usually would.” Most baseline sessions lasted for 10 min (the goal length). However, occasionally sessions were shorter (5–9 min) because of lack of target child cooperation. Treatment Sibling Training. The trainer taught the siblings to use the RIT techniques during two 15- to 30-min treatment sessions per week for 10 weeks. During training, the trainer made use of a manual written in child-friendly language and augmented with pictures depicting the intervention techniques. This manual is available from the first author by request. When introducing a new intervention technique, the trainer explained the technique and read through the relevant portion of the manual with the sibling, role-played the technique with the sibling while giving instruction and feedback, and demonstrated the technique with the child with autism while explaining her actions. In addition, after each technique was taught, a poster depicting the technique was placed in the playroom to remind the sibling to use the technique. Finally, the sibling used the technique while playing with the child with autism for 10 min. During half of this period, the trainer provided live feedback for the sibling. During the other half, the trainer
did not provide any suggestions or feedback. The half of this 10-min session during which feedback was provided alternated from session to session. To encourage the siblings to use the intervention strategies, parents were provided with a sticker chart to track siblings’ playtime outside of training sessions as well as how often the sibling practiced RIT techniques with the child with autism. Parents were asked to place one sticker on the chart for each 30 min of playtime between siblings and an additional sticker on the chart for each session in which siblings practiced RIT techniques. Siblings were reinforced for overall playtime and practicing RIT techniques with their choice of a small prize provided by the trainer each time they accumulated 10 stickers. Siblings were not initially reinforced for time spent during training sessions. However, after the 2nd week of training, Mark was reinforced with up to two stickers for making an effort to use the techniques correctly, as he found it difficult to maintain engagement and effort during the sessions as time went on.
Treatment Phases. To facilitate sibling learning, the intervention techniques were introduced in four phases. During Phase I (2 weeks), the siblings were taught to imitate the actions of their brothers with autism, including actions with toys, body gestures and movements, and vocalizations (contingent imitation). During Phase II (2 weeks), the siblings were taught to use simplified language (e.g., “Boy is driving”) to describe items and activities that were the attentional focus of the child with autism (linguistic mapping). In Phase III (3 weeks), the siblings were taught to alternate between imitating their brothers and providing opportunities for their brothers to imitate them, as well as to provide social praise for imitation attempts by the child with autism. Finally, in Phase IV (3 weeks), the siblings were taught to use gentle physical guidance to help their brothers with autism imitate if they did not do so spontaneously. See Ingersoll (2008) for a more detailed description of the intervention techniques. See Table 2 for a summary of sibling and child behaviors targeted during each treatment phase.
244
Generalization Probes. During baseline, at the end of the 10-week treatment, and at a 1-month follow-up, generalization sessions were conducted to determine whether skill gains generalized to untrained situations and maintained over time. To assess generalization to new materials, dyads were taped for 10 min playing with a set of novel toys provided by the experimenter. To assess generalization to a new setting, dyads were filmed interacting in a different setting in the home. To assess generalization of skills acquired by the child with autism, the target child was filmed interacting with another play partner not involved with the treatment. This child was a similar-aged female family friend for Patrick, Ryan, and Daniel and another sibling in the family for Chris (his 5-year-old sister). Finally, to assess maintenance of gains over time, the siblings were filmed approximately 1 month after completion of the intervention, interacting in the original setting and with the original materials.
Dependent Measures The 5-min, un-coached portion of each session was scored in order to examine the siblings’ independent use of the intervention strategies.
Sibling Behaviors. To determine if siblings learned to implement RIT techniques correctly, siblings’ fidelity of implementation of each intervention technique was coded from the videotaped play sessions. Contingent imitation and linguistic mapping were scored using 10-sec partial interval time sampling. Contingent imitation was defined as the sibling performing an action with or without a toy either simultaneously to the child performing the action or immediately following the child performing the action. Linguistic mapping was defined as the sibling commenting on or describing the child’s current focus of interest in a nondirective way. Asking questions or giving directions was not considered linguistic mapping. Use of the imitation training procedure was scored by recording all instances in which the sibling (a) provided an appropriate model for imitation (the child saw the model, the sibling used an attention-getting or descriptive phrase, and the sibling used a toy the child was already interested in), (b) provided a physical or verbal prompt for imitation, and (c) provided praise for correct spontaneous or prompted imitation. Use of each strategy was recorded separately and converted to rate per minute of correct use by dividing total instances of correct implementation by the length of the session.
Target Child Behaviors. Imitation was scored as a total percentage of models imitated. Joint engagement was scored as the percentage of 10-sec intervals in which the behavior occurred for at least half the interval. Joint engagement was defined as the target child and the sibling interacting with the
Journal of Positive Behavior Interventions 14(4) same object, and the target child showing evidence of awareness that the sibling was involved in the interaction (e.g., exchanging materials, eye contact, watching the sibling; Kasari, Gulsrud, Wong, Kwon, & Locke, 2010). Intervals in which the child spent 50% or more of the interval off camera or interacting with an adult were excluded from analyses of joint engagement.
Interrater Reliability All videotapes were coded by either the first author or undergraduate raters who were trained until reaching an acceptable reliability criterion (kappa ≥ .60, Pearson’s r ≥ .70) on at least three consecutive videos. Twenty-five percent of the behavioral observations were scored by a second rater who was blind to the treatment phase. For measures scored using interval scoring, Cohen’s kappa was calculated to determine interrater reliability. Cohen’s kappa was .63 for contingent imitation, .58 for linguistic mapping, and .72 for joint engagement. For frequency measures, Pearson’s r was used to calculate interrater reliability, with follow-up t tests to determine whether raters showed mean differences (Hartmann, 1977). The correlations between raters were .64 for modeling, .82 for prompting, .83 for praise, and .81 for imitation. All correlations were significant at p
Evaluation of a Sibling-Mediated Imitation Intervention for Young Children With Autism
Journal of Positive Behavior Interventions 14(4) 241–253 © 2012 Hammill Institute on Disabilities Reprints and permission: sagepub.com/journalsPermissions.nav DOI: 10.1177/1098300712437044 http://jpbi.sagepub.com
Katherine M. Walton, MA1 and Brooke R. Ingersoll, PhD1
Abstract Parents and peers have been successful at implementing interventions targeting social interactions in children with autism; however, few interventions have trained siblings as treatment providers.This study used a multiple-baseline design across six sibling dyads (four children with autism) to evaluate the efficacy of sibling-implemented reciprocal imitation training. All six typically developing siblings were able to learn and use contingent imitation, four of the six siblings were able to learn and use linguistic mapping, and all six siblings increased their use of at least one component of the imitation training procedure. Three of the four children with autism showed increases in overall imitation and all four showed evidence of increases in joint engagement. Parents and siblings reported high satisfaction with the intervention, and ratings by naïve observers indicated significant changes from pre- to posttreatment.These results suggest that sibling-implemented reciprocal imitation training may be a promising intervention for young children with autism. Keywords children with autism, family-based interventions, siblings, imitation
Autism is a pervasive developmental disorder that emerges early in childhood and has profound effects on social functioning and communication (American Psychiatric Association, 2000). Because of the significant social difficulties of children with autism, a large number of interventions for these children have focused on the development of social skills (see McConnell, 2002, for review). Interventions that have focused on teaching social interaction skills in natural settings and have involved social interaction partners with whom the child with autism is most likely to interact, such as parents and peers, have shown the best evidence of generalization and maintenance of these skills (Rogers, 2000). Research indicates that parents (e.g., Drew et al., 2002) and peers (e.g., McGee, Almeida, Sulzer-Azaroff, & Feldman, 1992; Pierce & Schreibman, 1995) can be successfully taught to implement intervention strategies, and these interventions lead to improvement in social communication skills for the children with autism. Much less research, however, has been devoted to training siblings as intervention providers. Involving siblings in social skill interventions for children with autism may be particularly successful as siblings spend a significant amount of time with each other in a variety of situations. Furthermore, siblings’ natural play patterns may provide more opportunities for social interactions and play initiations by the children with autism than those
of parents (El-Ghoroury & Romanczyk, 1999). However, typical siblings also make few attempts to interact with their siblings with autism during free play sessions (El-Ghoroury & Romanczyk, 1999), suggesting that they may benefit from instruction in techniques to facilitate social interaction with their brother or sister with autism. The few studies that have examined sibling-mediated interventions for children with autism indicate that this approach can be successful. For example, siblings have successfully used prompting and reinforcement strategies to increase play behaviors in their siblings with autism (Celiberti & Harris, 1993; Coe, Matson, Craigie, & Gossen, 1991). In a more extensive intervention, typical siblings of children with autism spectrum disorders (ASD) were taught a series of skills in 10 lessons, including staying in physical proximity to the child with ASD, gaining the child’s attention, creating opportunities for social interaction, 1
Michigan State University, East Lansing, MI, USA
Corresponding Author: Katherine M. Walton, Michigan State University, 69F Psychology Building, East Lansing, MI 48824, USA Email: [email protected] Action Editor: Aubyn Stahmer
242
Journal of Positive Behavior Interventions 14(4)
Table 1. Participant Characteristics at Intake Target child
Chronological age
Nonverbal skill levela
Language skill levelb
Ryan Patrick Daniel Chris
3 years 10 months 4 years 9 months
3 years 5 months 2 years 1 months
2 years 6 months >1 year 4 months
4 years 5 months 3 years 9 months
2 years 3 months 2 years 3 months
>1 year 4 months >1 year 4 months
Sibling
Sibling age
Baseline length
Mark Eric Andrea Lily Kristen Melissa
9 years 8 years 9 years 13 years 8 years 10 years
4 weeks 6 weeks 8 weeks 5 weeks 8 weeks 10 weeks
a
Bayley Scales of Infant Development, 3rd Edition, Cognitive Scale. MacArthur-Bates Communicative Development Inventory,Vocabulary Checklist.
b
organizing and negotiating about play ideas, offering and asking for help, asking for clear directions, and providing verbal feedback. The typical siblings were able to effectively use these skills with the child with ASD, leading to increases in social interaction (a targeted skill) and joint attention (a nontargeted skill) in the children with ASD (Tsao & Odom, 2006). Reciprocal imitation, in which partners imitate one another in extended turn-taking sequences, may offer another important treatment target for children with autism and their siblings, because it can facilitate social coordination between peers (Eckerman, Davis, & Didow, 1989). Reciprocal imitation training (RIT) is an intervention designed to increase reciprocal imitation skills in children with autism in a naturalistic social context (Ingersoll, 2008). RIT has been successful at increasing imitation in 2- to 4-year-old children with autism, with generalization to different settings, therapists, and materials, and maintenance over time (Ingersoll, 2010; Ingersoll, Lewis, & Kroman, 2007; Ingersoll & Schreibman, 2006). The intervention also increased joint attention, language, and play skills; these skills are theoretically related to imitation but were not directly targeted in the intervention (Ingersoll & Schreibman, 2006). Mothers of children with autism have also successfully implemented RIT with their children (Ingersoll & Gergans, 2007). This success as a parent-implemented treatment and the simplicity of the intervention suggest that it could be adapted for use as a sibling-implemented intervention. In the present study, we trained typically developing children to implement RIT with their younger brothers with autism. We assessed whether siblings correctly implemented the strategies involved in RIT and examined the effect of the intervention on imitation and joint engagement in the children with autism. We also examined whether skills learned during the course of the intervention generalized to different materials, settings, and typically developing play partners and maintained over time. Furthermore, we examined whether naïve observers were able to detect differences in the sibling interactions from pre- to posttreatment. Finally, we measured the acceptability of the intervention to parents and typically developing siblings.
Methods Participants Four young children with autism and six typically developing siblings participated. Target children were diagnosed by a professional with expertise in autism and exceeded the cutoff scores for “autism spectrum” on the social, communication, and social + communication algorithms of the Autism Diagnostic Observation Schedule–Module 1 (ADOS; Lord et al., 2000). At intake, children were administered the Bayley Scales of Infant Development, 3rd Edition cognitive scale (Bayley, 2006) to estimate nonverbal cognitive skills. Children’s primary caregivers completed the MacArthurBates Communicative Development Inventory (CDI; Fenson et al., 1993) as a measure of vocabulary development. Because the children were older than the norming sample ranges on the Bayley and CDI, age equivalents will be reported instead of standard scores (Table 1). Siblings were between the ages of 8 and 13. In families with more than one child who fell in the target age range, all siblings were invited to participate. In two families, two siblings were interested in participation. For these families, sessions were conducted separately for each sibling, and baseline lengths for the two siblings were staggered by 2 weeks. All siblings were reported to be developing typically, although Mark’s mother reported that he may have some undiagnosed sensory concerns.
Setting and Materials All sessions were conducted in the participants’ homes. One room in the home was chosen based on convenience for the family and for filming, and all sessions were conducted in this room. Seven to eight pairs of duplicate toys were provided by the sibling trainer at the beginning of baseline. Toys were chosen based on parent input, developmental appropriateness for the child with autism, and interest to the typically developing siblings. The children were encouraged to use these toys during the baseline and training sessions; however, they often used other toys that
243
Walton and Ingersoll Table 2. Summary of Behaviors Targeted in Each Treatment Phase Sibling behaviors Treatment phase Phase I Phase II Phase III Phase IV
Contingent imitation
Linguistic mapping
X X X X
X X X
Modeling
Child behaviors Prompting
X X
X
Praise
X X
Joint engagement
Imitation
X X X X
X X
Note. Behaviors marked with an “X” were targeted in the indicated treatment phases.
were accessible in the filming space in addition to these toys.
Procedure A multiple-baseline design was conducted across dyads. The trainer (first author) visited the participants’ homes twice a week throughout baseline and treatment. She was a graduate-level student with approximately 2 years of experience working with young children with ASD. She had been trained in direct implementation of RIT by the second author and had been using RIT for approximately 1 year. Sessions were videotaped for later scoring.
Baseline. During baseline sessions, the sibling was instructed to “Play with your brother like you usually would.” Most baseline sessions lasted for 10 min (the goal length). However, occasionally sessions were shorter (5–9 min) because of lack of target child cooperation. Treatment Sibling Training. The trainer taught the siblings to use the RIT techniques during two 15- to 30-min treatment sessions per week for 10 weeks. During training, the trainer made use of a manual written in child-friendly language and augmented with pictures depicting the intervention techniques. This manual is available from the first author by request. When introducing a new intervention technique, the trainer explained the technique and read through the relevant portion of the manual with the sibling, role-played the technique with the sibling while giving instruction and feedback, and demonstrated the technique with the child with autism while explaining her actions. In addition, after each technique was taught, a poster depicting the technique was placed in the playroom to remind the sibling to use the technique. Finally, the sibling used the technique while playing with the child with autism for 10 min. During half of this period, the trainer provided live feedback for the sibling. During the other half, the trainer
did not provide any suggestions or feedback. The half of this 10-min session during which feedback was provided alternated from session to session. To encourage the siblings to use the intervention strategies, parents were provided with a sticker chart to track siblings’ playtime outside of training sessions as well as how often the sibling practiced RIT techniques with the child with autism. Parents were asked to place one sticker on the chart for each 30 min of playtime between siblings and an additional sticker on the chart for each session in which siblings practiced RIT techniques. Siblings were reinforced for overall playtime and practicing RIT techniques with their choice of a small prize provided by the trainer each time they accumulated 10 stickers. Siblings were not initially reinforced for time spent during training sessions. However, after the 2nd week of training, Mark was reinforced with up to two stickers for making an effort to use the techniques correctly, as he found it difficult to maintain engagement and effort during the sessions as time went on.
Treatment Phases. To facilitate sibling learning, the intervention techniques were introduced in four phases. During Phase I (2 weeks), the siblings were taught to imitate the actions of their brothers with autism, including actions with toys, body gestures and movements, and vocalizations (contingent imitation). During Phase II (2 weeks), the siblings were taught to use simplified language (e.g., “Boy is driving”) to describe items and activities that were the attentional focus of the child with autism (linguistic mapping). In Phase III (3 weeks), the siblings were taught to alternate between imitating their brothers and providing opportunities for their brothers to imitate them, as well as to provide social praise for imitation attempts by the child with autism. Finally, in Phase IV (3 weeks), the siblings were taught to use gentle physical guidance to help their brothers with autism imitate if they did not do so spontaneously. See Ingersoll (2008) for a more detailed description of the intervention techniques. See Table 2 for a summary of sibling and child behaviors targeted during each treatment phase.
244
Generalization Probes. During baseline, at the end of the 10-week treatment, and at a 1-month follow-up, generalization sessions were conducted to determine whether skill gains generalized to untrained situations and maintained over time. To assess generalization to new materials, dyads were taped for 10 min playing with a set of novel toys provided by the experimenter. To assess generalization to a new setting, dyads were filmed interacting in a different setting in the home. To assess generalization of skills acquired by the child with autism, the target child was filmed interacting with another play partner not involved with the treatment. This child was a similar-aged female family friend for Patrick, Ryan, and Daniel and another sibling in the family for Chris (his 5-year-old sister). Finally, to assess maintenance of gains over time, the siblings were filmed approximately 1 month after completion of the intervention, interacting in the original setting and with the original materials.
Dependent Measures The 5-min, un-coached portion of each session was scored in order to examine the siblings’ independent use of the intervention strategies.
Sibling Behaviors. To determine if siblings learned to implement RIT techniques correctly, siblings’ fidelity of implementation of each intervention technique was coded from the videotaped play sessions. Contingent imitation and linguistic mapping were scored using 10-sec partial interval time sampling. Contingent imitation was defined as the sibling performing an action with or without a toy either simultaneously to the child performing the action or immediately following the child performing the action. Linguistic mapping was defined as the sibling commenting on or describing the child’s current focus of interest in a nondirective way. Asking questions or giving directions was not considered linguistic mapping. Use of the imitation training procedure was scored by recording all instances in which the sibling (a) provided an appropriate model for imitation (the child saw the model, the sibling used an attention-getting or descriptive phrase, and the sibling used a toy the child was already interested in), (b) provided a physical or verbal prompt for imitation, and (c) provided praise for correct spontaneous or prompted imitation. Use of each strategy was recorded separately and converted to rate per minute of correct use by dividing total instances of correct implementation by the length of the session.
Target Child Behaviors. Imitation was scored as a total percentage of models imitated. Joint engagement was scored as the percentage of 10-sec intervals in which the behavior occurred for at least half the interval. Joint engagement was defined as the target child and the sibling interacting with the
Journal of Positive Behavior Interventions 14(4) same object, and the target child showing evidence of awareness that the sibling was involved in the interaction (e.g., exchanging materials, eye contact, watching the sibling; Kasari, Gulsrud, Wong, Kwon, & Locke, 2010). Intervals in which the child spent 50% or more of the interval off camera or interacting with an adult were excluded from analyses of joint engagement.
Interrater Reliability All videotapes were coded by either the first author or undergraduate raters who were trained until reaching an acceptable reliability criterion (kappa ≥ .60, Pearson’s r ≥ .70) on at least three consecutive videos. Twenty-five percent of the behavioral observations were scored by a second rater who was blind to the treatment phase. For measures scored using interval scoring, Cohen’s kappa was calculated to determine interrater reliability. Cohen’s kappa was .63 for contingent imitation, .58 for linguistic mapping, and .72 for joint engagement. For frequency measures, Pearson’s r was used to calculate interrater reliability, with follow-up t tests to determine whether raters showed mean differences (Hartmann, 1977). The correlations between raters were .64 for modeling, .82 for prompting, .83 for praise, and .81 for imitation. All correlations were significant at p
