Observer-Reported Communication Ability (ORCA) Measure

What is ORCA?

The ORCA Measure is a questionnaire that assesses the communication ability of individuals with neurodevelopmental disorders that significantly impact verbal speech. The intended use of the ORCA measure is to assess an individual’s baseline communication ability level and subsequent changes in communication ability over time in a research study. The measure consists of 84 total questions with 70 behavioral items within 22 concepts/functions (e.g., refuse object, make choices) that cover expressive, receptive and pragmatic areas of communication, alongside a set of 14 descriptive items that capture important information about the individual’s unique ways of communicating (e.g. modalities the individual uses, their current vocabulary, and language complexity). The questionnaire is designed to be completed by the primary caregiver who is most familiar with the individual and the ways they communicate. The descriptive items follow skip logic, so it is possible not every caregiver will complete every question.

The development of the ORCA measure was funded by the Foundation for Angelman Syndrome Therapeutics (FAST) and is currently available in English with language translations in:

Arabic Israel Hebrew Israel
Dutch Netherlands Italian
English Australia Polish Poland
English Canadian Portuguese Portugal
English UK Russian Russian Federation
French Canada Spanish Spain
French France Spanish USA
German Germany Turkish Turkey

The ORCA Design

The ORCA measure’s content was developed using rigorous quantitative methods and qualitative interviews with parents of individuals with Angelman syndrome (AS) and by communication specialists (e.g., speech-language pathologists) who treated individuals with AS and other developmental communication disorders. The team developed questions from the caregiver’s perspective and the questionnaire’s target population was any AS individual (of any genotype) aged 2 years or older (including adults with AS). The ORCA was purposely designed to be inclusive of all modalities (i.e. ways of communicating)—meaning that an individual’s ability is scored whether they use gestures/signs, words, assistive technology, or a combination of these to communicate.

Although the ORCA measure has not been validated in populations outside of AS, it may be applicable to other similar neurodevelopmental disease groups. Ideally, these should be populations where most individuals are nonverbal or communicate primarily through modalities other than spoken words. If you are interested in using the ORCA measure in a population other than AS, please click here for more information and guidance. 


For more information about the ORCA, view our FAQs
Questions? Contact Nicole Lucas


The ORCA measure is free to use for noncommercial purposes (e.g. research and education). The ORCA Measure is a copyright Duke University. Pattern Health is the exclusive authorized distributor of the ORCA Measure. If you are interested in obtaining a license to use the ORCA measure, please fill out a license request form.

Expanded ORCA Measure

Read more about the Expanded ORCA measure

Study Team

Bryce Reeve, PhD
Director, Center for Health Measurement
Kelly Gordon
Speech Pathologist
Dr. Harrison Jones
Associate Professor of Head and Neck Surgery and Communication Sciences
Molly McFatrich
Administrative Director
Assistant Professor in Population Health Sciences
Nicole Lucas
Research Program Leader
Li Lin
Senior Biostatistician