The intervention is often used in conjunction with the Picture Exchange Communication System (PECS) as it primes the child for an easy transition between treatment types. The PECS program serves as another common intervention technique used to conform individuals with autism. As many as 25% of autistic individuals have no functional speech. The program teaches spontaneous social communication through symbols or pictures by relying on ABA techniques. PECS operates on a similar premise to DTT in that it uses systematic chaining to teach the individual to pair the concept of expressive speech with an object. It is structured in a similar fashion to DTT, in that each session begins with a preferred reinforcer survey to ascertain what would most motivate the child and effectively facilitate learning.