This study aims to understand how different ways of communication affect behavior in individuals with intellectual and/or developmental disabilities (IDD). People with IDD sometimes have trouble communicating and may show challenging behaviors like aggression. The study will look at if using a preferred way to communicate, like picture cards or a tablet app, helps maintain positive behavior better than a less preferred way.

Participants will be divided into two groups. Group 1 will start with the preferred communication method, and Group 2 will start with a less preferred method. Later, they will switch methods to see which works better. The goal is to reduce challenging behaviors by finding the best communication method for each person.

• 60 people with IDD will join the study, and at least 48 need to complete it.
• Participants must be 2 years or older and have specific communication needs.
• The study involves switching communication methods, which might take some time and effort.