Use of the Differential Abilities Scale for the Assessment of Children with Autism Spectrum Disorders

Background: Children with autism spectrum disorders can be particularly challenging to assess using standardized measures when one considers the type of behavior required for a psychological evaluation. For example, many intelligence assessments require participants to imitate the actions of the administrator, to answer questions verbally, and to understand the directions given by the administrator. It is imperative that intelligence assessments not only provide a valid and reliable assessment of children, but also allow for administration that minimizes disruptive behaviors and maximizes attention during the process. Unfortunately, few studies have documented the behavior of children with ASD during the assessment process.

Objectives: In order to better understand the assessment process, the following research questions are posed:

1.  What is the relationship between intelligence, language abilities, and autism severity for children with ASD?

2.  What are the patterns of test session behavior displayed by children with ASD during the assessment?

3.  Are observed testing behaviors related to the level of performance on the intelligence assessment?

Methods: The Differential Abilities Scales was administered to 48 children with ASD who were between the ages of 3 and 8 years old. In order to examine the relationship between language abilities and intelligence, the Oral and Written Language Scales was administered to all participants. The Childhood Autism Rating Scales was also completed during the assessment sessions in order to examine the relationship between autism severity and intelligence amongst the participants. All assessments were videotaped for further analysis of the participants’ testing behavior. Videotaped test sessions will be coded by two raters for both off task and on task behaviors in 10-second intervals using the procedure and coding manual detailed by Akshoomoff (2006). 

Results: Simple linear regression will be used to describe the relationship between scores obtained on the DAS and the OWLS.  Pearson’s correlation will also be employed to explore the relationship between the CARS and the DAS. Descriptive analyses will be used to explore the patterns of on and off task behaviors of the participants during the intelligence assessment sessions.  To address the relationship between observed test session behavior and scores obtained on the DAS, partial correlations will be performed using the amount of time engaged in on task and off task behaviors and the General Conceptual Ability score and subscale scores obtained by the participants, while holding constant language abilities and autism severity.

Conclusions: An analysis of the data is still ongoing; however, it is anticipated that a linear relationship will be demonstrated between language abilities and intelligence for children with ASD. It is also hypothesized that autism severity will be related to certain aspects of intelligence as measured by the DAS. It is also anticipated that the children in the study will exhibit more off task behaviors than on task behaviors, and that a relationship will be found between test session behaviors and scores obtained on the intelligence assessment.