Of the available standardized diagnostic instruments for autism spectrum disorders, the Autism Diagnostic Observational Schedule (ADOS) and the Autism Diagnostic Interview- Revised (ADI-R) are the most commonly used. Currently, both the ADOS and ADI-R are available in twelve languages, and although Chinese mandarin is the primary language for 1.2 billion people worldwide, it is not available in this language. A previous project completed by a team of experts assembled by Dr. Lee has collected preliminary data from translated screening instruments such as the SCQ had identified cultural factors which should be modified to make the testing instrument valid. The unavailability of proper diagnostic tools in Chinese has been one of the major barriers for autism researchers who conduct research in Chinese speaking populations. To fill the gap and facilitate future autism research in Chinese speaking populations, this application will both translate and adapt the ADOS and ADI-R into Chinese mandarin and train Chinese-speaking clinicians to become research reliable on these diagnostic instruments so a later prevalence study can be conducted in this country. What this means for people with autism: Data collected using the Chinese versions of the ADOS and ADI-R will allow multi-national and multi-racial/ethnic comparisons in variations and similarities of ASDs using the same diagnostic criteria and case definitions. This will allow researchers to examine the prevalence and incidence of autism in a country with different genetic and environmental factors to better understand the causes of autism.