Ayres Sensory Integration (ASI) Therapy is an individualized intervention designed to address specific underlying sensorimotor issues that may affect children's performance during daily routines and occupations. The intervention takes place in the context of play, emphasizes the active participation of the child, involves a collaborative relationship between the occupational therapist and the child, and focuses on participation-oriented outcomes that are collected at regular intervals throughout the intervention program. In general, its content is to improve the child's occupational performance.

The program, which will be carried out in accordance with the Ayres Sensory Integration Fidelity Measure®, it is aimed to reduce the autism-specific symptoms of the child with autism and the dependence of the child on the caregiver in self-care activities. It is predicted that this whole process will increase the participation and his performance of the child with autism in his occupations related to his daily life.

H0: Ayres Sensory Integration Therapy has no effect on the occupational performance of the child with autism spectrum disorder.

Inclusion Criteria:

• Children diagnosed with Autism Spectrum Disorder according to Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition
• Level 1 (requiring support) and Level 2 (requiring substantial support) are severity levels for Autism Spectrum Disorder
• Age at first and second test between 3 years and 10 years

Exclusion Criteria:

• Accompanying neurodevelopmental, psychiatric, neurological or physical diagnosis