A quantitative analysis of language interventions for children with autism.

Autism is not only of the most prevalent developmental disabilities, but it is also the fastest growing according to the Autism Society of America, (2008). The Center for Disease Control and Prevention statistics indicate that 1 in 150 8-year-old children in the United States have an autism spectrum disorder (CDC; 2007). The rising incidence may be due to increased awareness, early identification markers and screenings, and more sensitive and specific assessment diagnostic instruments. As the number of children with the disorder rises, so too does the need for qualified therapists and effective interventions to maximize each child's full potential. As such, the CDC recommends that individuals diagnosed with autism receive evidence-based, early intervention services as soon as possible (CDC; 2007). According to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV; 1994), autism spectrum disorder (ASD) is described by significant deficits in three behavioral domains: 1) qualitative impairment in social interaction, 2) qualitative impairment in communication, and 3) restricted, repetitive and stereotyped patterns of behavior, interests, and activities. Communication deficits include a delay in the development of spoken language. When language does develop, impairments in conversational language occur with high frequency (DSM-IV; 1994). Many instructional models (e.g. discrete trial teaching, incidental teaching, pivotal response training) specifically teach spoken language as part of the instructional sequence to remediate these debilitating communication deficits. As stated above, there are multiple approaches used to teach individuals with developmental disabilities spoken language just within the field of applied behavior analysis (ABA). Historically, the approach most associated with ABA is discrete trial teaching (DTT). Discrete trial teaching is a systematic and structured teaching methodology, consisting of "discrete" trials. A discrete trial consists of one concise instruction, a learned response, and a consequence highly controlled by an instructor. Discrete trial teaching sessions generally occur at an isolated table in a designated area of a home or school and thus the model has received significant criticism over the years (Steege, Mace, Perry, & Longnecker, 2007). Therefore, for purpose of this investigation, all research using DTT is referred to as contrived approaches because the instructional strategy is not "typical" of a naturalistic setting. In addition to the setting and approach being contrived, discrete trial critics have argued that there is a lack of skill generalization, that the instructional approach only produces rote responding, and that there is an inability to teach sequential chains since instruction only occurs as discrete trials (Steege et al., 2007; Sundberg & Partington, 1998). For these reasons, critics have referred to DTT as an analog training condition and not likely to generalize to natural contingencies of reinforcement. Autism interventions have also evolved to address some of the criticisms of DTT and to better address the needs of the population. Some researchers worked toward altering teaching strategies in hopes of achieving more promising outcomes. For instance, Koegel, O'Dell, and Koegel (1987) conducted a study in which they manipulated teaching variables to include more functional teaching stimuli, naturalistic reinforcers, and teaching within the natural environment. The results of this study suggest that these teaching methods resulted in greater generalization of language skills. In addition, other ABA approaches have emerged that specifically focus on training in the natural environment and are thus called, naturalistic approaches. Naturalistic approaches include incidental teaching (Hart & Risley, 1975, 1982), natural environment teaching (Sundberg & Partington, 1998), pivotal response training (Koegel, Koegel, Harrower, & Carter, 1999), and enhanced milieu teaching (Hancock & Kaiser, 2002). …