According to the introduction, the critical factor in assessing the ability to give or deny consent to sexual practices is the developmentally disabled person's ability to say no adequately. The fact sheet outlines elements to legally valid consent and details standards of competency that apply to developmentally disabled persons. Definitions are given for mental retardation, adaptive behavior, and rape under California law. Techniques for testing cognitive functions -- awareness, orientation, memory, perception, and learning -- are described. Guidelines to assessing the validity of the informed consent process conclude the fact sheet.