2. This finding has important implications for measures of autism severity across school and home.

4. To examine change in parent-teacher concordance over time

5. To examine if parent- teacher concordance differs with level of child impairment.

6. Parent- teacher agreement on the SRS was found to be much lower than previously reported and varied by time, symptom severity, and subscale.

7. There was less parent-teacher concordance for children who are less severely affected by autism than for children who are more severely affected.

8. Agreement on the Autistic Mannerisms subscale was poor, which suggests autistic mannerisms as measured by the SRS may vary by environmental context.

9. Further research is required to determine if disagreement on the SRS is a product of rater bias or if social functioning varies between the home and school environments.

11. The Parent and Teacher SRS was administered at baseline and 7 months later.

12. A General Demographics Survey was completed by a parent/guardian to confirm the heterogeneity of the sample.

13. Children were evaluated with the ADOS to confirm diagnosis.

14. ADOS Severity Score used to measure ASD severity.