This research aimed to compare the effectiveness of Applied Behavior Analysis (ABA) and TEACCH training methods in improving social skills and verbal comprehension in children with an autism spectrum disorder.

The current study is an intra-group type (single subject) in terms of its practical purpose and execution method. A multi-baseline design was employed using different methods and people. The statistical population consisted of all students with an autism spectrum disorder in the elementary schools of Mazandaran Province in the academic year of 2017-2018. The sample group included four people in two groups and each group had two members who were assigned randomly. Data collection tools were Weiland Social Development Scale and Wechsler Children's Scale. The statistical tests consisted of visual and statistical analyses, as well as examining the process of changes in the subject. The intervention method was the observation of the subject's line in the baseline and the training of the intervention package together with the follow-up of the process of changes, which lasted for two months.

The findings showed that the effect of ABA and TEACCH on improving social skills and verbal comprehension in children with an autism spectrum disorder is different and according to the indicators of improvement (8.83 and 15.13 for social skills) and (scores of 160 and 100 for verbal comprehension), TEACCH has a greater contribution.

The study showed that tichs treatment method was more effective in improving socoal slills and verbal comprehension in two subjects than ABA treatment due to its structutrd nature.