This is a research study that will assess the effects of a Pivotal Response Treatment Online Training Course (PRT-O) for training parents of children with Autism Spectrum Disorder (ASD). The study will specifically investigate whether participants can learn to deliver PRT effectively following participation in the Online training.

Inclusion Criteria:

• 2:0 to 5:11 years at the time of consent,
• diagnosed with ASD (based on history, review of available medical records including diagnostic testing, e.g., Autism Diagnostic Observation Schedule) or suspicion of Autism Spectrum Disorder diagnosis, and confirmed with Autism Diagnostic Interview-Revised (ADI-R),
• with significant adaptive communication deficits (i.e., either a Vineland-3 Communication subscale 2 Standard Deviations below average for 2 and 3 year olds and 3 Standard Deviations below for 4 and 5 year olds or a Vineland-3 Expressive V-scale Score 2 Standard Deviations below average for 2 and 3 year olds, or 3 Standard Deviations below for 4 and 5 year old, and at least moderate severity on the Clinical Global Impressions Severity (CGI-S) language subscale),
• an English-speaking parent able to consistently participate in study procedures and conduct treatment in English,
• stable psychotropic medication(s) or biomedical intervention(s) for at least 1 month prior to baseline measurements with no anticipated changes during study participation,
• stable treatment (ABA, Floortime, or other interventions), speech therapy, and school placement for at least 1 month prior to baseline measurements with no expected changes during study participation,
• no more than 60 minutes of 1:1 speech therapy per week

Exclusion Criteria:

• Children who have a primary language other than English
• parent or child diagnosed with severe psychiatric disorder or unstable medical problem
• previous adequate trial of pivotal response treatment resulting in parent meeting Pivotal Response Treatment fidelity of implementation at baseline
• Receiving more than 15 hours of in home 1:1 ABA per week
• living within 100 miles of Stanford University.