This clinical trial is testing how different ways of communicating help people with intellectual or developmental disabilities maintain better behavior. Some people use a "touch talker" (a device that talks when touched), while others use "picture cards" (cards with images). The study checks which way works better long-term and explores if age or symptom severity affects results. Participants are split into two groups: one starts with their favorite communication method, and the other with a less favored but still effective method. Later, they switch methods to see which one helps them stick to good behavior.

• Participants must be at least 2 years old and have intellectual or developmental disabilities.
• The study involves trying out two different communication methods.
• Researchers will track if communication methods reduce challenging behaviors like aggression.