Naturalistic behavioral parent training programs have traditionally focused on teaching parents prompting and reinforcement strategies to increase their child’s use of core social-communication skills such as language and imitation. In one of the earliest studies of parent training for children with autism, Laski et al. (1988) examined the efficacy of training parents of children with ASD to use the Natural Language Paradigm to promote their children’s spontaneous speech. Results from this study indicated that all parents increased their use of the intervention techniques, and all children increased their rate of vocalizations. Parents and children generalized their newly learned skills to additional non-training environments (Laski et al. 1988). In a different study, Kaiser and colleagues (2000) taught six mothers of children with autism to implement Enhanced Milieu Teaching (EMT) strategies to promote their children’s spontaneous verbal language. All parents increased their correct use of the EMT techniques from baseline to intervention sessions, with five out of the six mothers achieving criterion level fidelity of implementation during the 24-session training program. Moreover, all six children showed increases in their total use of communication targets; however, increases in spontaneous use of communication targets were variable across individual children. Most parents and children in this study were able to generalize use of skills across the majority of situations and over a period of time (Kaiser et al. 2000). Nefdt and colleagues (2009) created a computerized self-directed learning program for parents of children with ASD that taught motivational techniques from pivotal response training (PRT) to increase their children’s social-communication, primarily verbal language. After the use of the computerized training program, parents were able to implement PRT strategies with fidelity, provided more language opportunities for their children, and displayed greater confidence when interacting with their children. Moreover, children of these parents demonstrated increases in their use of verbal language (Nefdt et al. 2009). Finally, Ingersoll and Gergans (2007) evaluated the efficacy of training parents to use a naturalistic behavioral intervention, reciprocal imitation training (RIT), in order to improve imitation skills in children with ASD. Parents were able to increase their use of intervention techniques in a lab setting as well as during play interactions with their children at home. Additionally, children in the study increased their spontaneous imitation with objects during lab sessions and were able to generalize these skills to their home environments. Taken together, these studies suggest that parents can be taught to implement naturalistic behavioral techniques with a high degree of fidelity to promote gains in their child’s use of core social-communication skills.

A different, and growing, body of research suggests that parent-mediated developmental or social-pragmatic interventions can also lead to important gains in social-communication skills in children with ASD. These developmental parent training programs typically focus on enhancing the parent-child relationship and promoting child skills such as social engagement, shared affect, and social reciprocity (Brookman-Frazee et al. 2009). Many of the early evaluations of developmental parent-mediated intervention programs did not use experimental designs; although changes in important outcome measures were observed, it was difficult to attribute these changes to the parent training directly (Ingersoll 2010a). For example, Mahoney and Perales (2003) examined the effect of Responsive Teaching, a parent-mediated intervention, for 20 children with ASD using a pre-post study. Results from this study indicated that a majority of parents became more responsive with their children during participation in the program and a majority of children demonstrated significant gains in social-emotional skills, including social competence. Improvements in parents’ responsiveness was associated with child gains in social-emotional skills. However, there were no controls in this particular study making it impossible to parse out maturational and other effects from the impact of the parent training program (Mahoney and Perales 2003). Recently, a handful of controlled trials of parent-mediated developmental interventions have been conducted to address limitations of the early work in this area. For example, McConachie and colleagues (2005) evaluated the effect of Hanen’s More than Words curriculum (Sussman 1999), a developmental parent-mediated intervention, on parents’ ability to facilitate social-communication in their children with ASD. Parents who participated in the program used significantly more facilitative strategies during parent-child interactions than did parents in the control condition. Moreover, parents who received training indicated larger gains in child vocabulary than did parents in the control group. Green and colleagues (2010) evaluated the effect of a parent-mediated communication-focused intervention, Preschool Autism Communication Trial (PACT), on parent and child outcomes. Results from this study suggest that parents in the PACT group improved their parental synchrony with their child and rated their children as having greater improvements in language and social-communication skills than did the parents of children in the treatment as usual group. The results of investigations of developmental parent training programs suggest that parents can learn to increase their responsiveness in order to facilitate the development of social-communication skills in their children with ASD.

Although the underlying theoretical tenets of naturalistic behavioral and developmental approaches differ, they are actually quite similar in terms of the intervention techniques utilized to help parents promote their child’s social-communication skills (Ingersoll 2010a). Appreciating these similarities, researchers have begun to examine parent-mediated interventions that integrate intervention techniques from both approaches in order to further enhance the social-communication skills of children with ASD (Ingersoll and Dvortsack 2006). In a pilot study of the Early Start Denver Model (Vismara et al. 2009), investigators examined the impact of participation in a blended program on parental skill acquisition and child social-communication skills. Seven out of eight parents were able to achieve mastery of implementation of the intervention techniques after participating in the program for 6 weeks. Moreover, these parents retained high levels of implementation fidelity over the next several months. Additionally, children whose parents completed the program demonstrated increases in social-communication skills including expressive language. A pilot study of another blended parent training program, Project ImPACT (Ingersoll and Dvortscak 2010), found similarly encouraging results for the use of such an approach (Ingersoll and Dvortsak 2006). The format of this particular parent training program was developed to be compatible with classroom-based intervention models, and thus the parent training can be conducted by clinicians as well as classroom teachers. Results from the pilot study revealed that parents increased their understanding of the intervention techniques, were highly satisfied with training format, and attributed gains in their child’s social-communication skills to the program. A follow up study of Project ImPACT (Ingersoll and Wainer in press) found that the parent training program could be effectively implemented by educators in early childhood classroom settings to produce improvements in parent’s fidelity of intervention implementation, decreases in parental stress, and improvements in child social-communication skills.

The majority of empirical research on parent-mediated interventions for children with ASD has examined the efficacy and effectiveness of teaching various intervention techniques to parents to promote social-communication, and thus early socialization skills. Across studies, there is emerging evidence to suggest that these approaches can increase early social-communication skills in young children with ASD and that gains are maintained over time. As such, teaching parents how to promote their child’s social-communication during daily routines and activities is recommended practice for ASD intervention (NRC 2001). Although research indicates that parent training can lead to gains in parents’ implementation of intervention techniques, the differential effectiveness of various delivery formats, training procedures, and training materials on parental learning is less clear; nonetheless, a number of training models appear to be effective.

The 1997 Reauthorized Individuals with Disabilities Education Act (IDEA) stipulates that individuals with disabilities, including those with ASD, should be educated in the “least restrictive environment” suitable for their educational needs. This enables students with ASD to have maximal access to normalized settings and typically developing peers, and to be “included” in classrooms with typically-developing peers. Given this provision, inclusion of children with ASD in classrooms with typically-developing students is a goal for many students with ASD. While typically developing students may be able to serve as models for appropriate social behavior and potential friends for children with ASD, simply placing children with ASD in classrooms with typically developing peers does not guarantee that students with ASD will improve their social interaction skills or form meaningful friendships (Mesibov and Shea 1996). In addition, placing children with ASD in regular classroom settings without additional support may be difficult or impossible for students with greater support needs. Therefore, recent models of inclusion advocate that educational placement in a typical classroom should be accompanied by careful educational planning and the use of a number of empirically supported intervention techniques (including the peer-mediated intervention strategies described below) in order to be most beneficial to children with ASD (Harrower and Dunlap 2001; Simpson et al. 2003).

One way of supporting socialization between children with ASD and typically developing peers in an integrated classroom setting is by arranging the classroom situation to promote interactions between children with ASD and their typically developing peers. A classroom environment with structured activities which lend themselves to cooperation among peers, facilitated by adults, may increase the chance of successful social interactions between children with ASD and typically developing peers. For example, the integrated playgroup model typically includes a consistent schedule and routine with play activities appropriate to the developmental level of the children with ASD (Wolfberg and Schuler 1993). In addition, a small number of familiar typically developing peers are involved, and an adult closely monitors the play interactions and encourages the children to become involved in joint activities. Integrated playgroups using these components have led to increased interaction between children with ASD and peers as well as increases in appropriate play behavior in children with ASD (Roeyers 1996; Wolfberg and Schuler 1993).

Some peer-mediated intervention programs have provided additional impetus for children with ASD to interact directly with their typically developing peers by assigning typically developing peers to serve as “peer buddies” or “peer tutors” for children with ASD (e.g. Garrison-Harrell et al. 1997; Haring and Breen 1992; Kamps et al. 1997). In the peer buddy model, typically developing students are paired with students with ASD to serve as social supports for these students. Typically developing students are educated about the student with whom they are paired (e.g. taught how to use an augmentative communication system, taught to engage in or support specific social interaction behaviors) and may also be reinforced by teachers for engaging in positive interactions with their peer buddies. A related intervention model, a peer network model, pairs a number of students with the student with ASD, rather than using 1:1 pairs. This provides the student with ASD an opportunity to increase his social engagement with a larger number of peers. This approach has been found to be successful for increasing peer acceptance of students with ASD and frequency and duration of social interactions between the students with ASD and trained peers (Garrison-Harrell et al. 1997; Kamps et al. 1997) in young school-aged children. Haring and Breen (1992) reported similar results of a peer network approach when used with two 13-year-old boys with disabilities.

While peer buddy and peer network interventions pair students with the specific goal of promoting social interactions, peer tutoring interventions involve typically developing students as educational supports for children with ASD. In the peer tutoring model, typically developing students are taught to serve as academic tutors (e.g. in reading or math) for students with ASD. Typically developing students are taught specific tutoring skills and then paired with students with ASD. Peer tutoring interventions led not only to improved academic performance for the students with ASD, but also to increased social interactions during free time for these students, when compared to teacher-led programs (Dugan et al. 1995; Kamps et al. 1994, 1999). Peer tutoring has also been used to teach adaptive skills to lower-functioning students with ASD, with improved responding of students with ASD to typical peers reported over time, in addition to mastery of targeted adaptive behaviors (Blew et al. 1985). These studies suggest that pairing students with ASD with typically developing students can lead to social interaction gains for students with ASD, whether or not social skills are specifically targeted in the relationship.

While the previously described interactions have set up situations in specific ways in the hopes of facilitating social interaction between children with ASD and typical peers (e.g., by arranging the setting in specific ways or pairing children with ASD with typical peers), a number of interactions have directly taught peers skills specifically targeted at successfully initiating social interactions with students with ASD. A number of studies have demonstrated increases in the social interactions of young children with ASD when peers are trained to initiate interactions using “play organizers” such as helping, sharing, giving affection, and praise (e.g. Goldstein et al. 1992). These interventions have demonstrated robust changes in social interactions of children with ASD, including generalization to untrained peers. Generalization and maintenance have been strongest when multiple peers are trained in the intervention and peers are taught to self-monitor after adult prompting and reinforcement is faded (Rogers 2000 for review). These same interventions have also been used successfully to improve interactions between children with ASD and their siblings, with parents serving as teachers for the typically developing siblings (Strain and Danko 1995; Strain et al. 1994).

A final class of peer- and sibling-mediated interventions has adapted skill-building treatments such as Pivotal Response Training and Incidental Teaching for use by typically developing peers and siblings. These treatments have been effective at increasing child skills (e.g. language, joint attention, play skills) when delivered by adults. Therefore, having peers or siblings deliver these treatment components may potentially confer the double advantage of building specific skills in the child with ASD while also promoting peer and sibling socialization skills. Interventions that have been adapted for use in peer- and sibling-mediated components consisted of skills such as modeling, prompting, and reinforcement in naturalistic settings and have been used with children as young as preschool-aged. McGee et al. (1992) taught preschool-aged children in an inclusive classroom to use incidental teaching with their peers with ASD. Incidental teaching consists of using preferred play materials to create opportunities to prompt and reinforce language use. McGee et al. (1992) found increases in reciprocal social behavior, social initiations, and peer acceptance following the use of peer-mediated incidental teaching. Peers have also successfully used Pivotal Response Training techniques, including modeling, shaping, and reinforcement, to improve social interactions in school-aged children with ASD (Pierce and Schreibman 1997).