school and work task organization, among others . Intellectual capacity, education, motivation,
socialization, personality features, vocational opportunity, cultural experience, and coexisting
general medical conditions or mental di sorders influence adaptive functioning.
Adaptive functioning is assessed using both clinical evaluation and individualized,
culturally appropriate, psychometrically sound measures. Standardized measures are
used with knowledgeable informants (e.g., pa rent or other f amily member; teacher; coun-
selor; care provider) and the individual to th e extent possible. Additional sources of infor-
mation include educational, developmental, medical, and mental health evaluations.
Scores from standardized measures and interv iew sources must be interpreted using clin-
ical judgment. When standardized testing is di fficult or impossible, because of a variety of