According to Reynolds and Dombeck (2006), the main aim of discrete trial training is to teach the learner how to pay attention and how to communicate.
"Therapists are ultimately interested in getting children to pay attention to task learning and in developing their ability to respond appropriately to communication. Letters, numbers and object labeling skills are thus acquired as a byproduct of discrete trials training. Because communicative skills are basic and fundamental and must be present before more complex social skills can be taught, they are taught early on in the process."
Once these basic skills have been taught, the learner is ready to acquire other skills, such as dressing, eating, making a bed etc. However, acquiring communication is often considerably more complicated than this and is often the main lifelong learning need for children with significant autism
There have been various claims made for discrete trial training. For example
According to a review by Smith (2001)
"'For children with autism, DTT is especially useful for teaching new forms of behavior (e.g., speech sounds or motor movements that the child previously could not make) and new discriminations (e.g., responding correctly to different requests). DTT can also be used to teach more advanced skills and manage disruptive behavior."
In practice, DTT often produces changes in very specific skills, such as naming things like objects or colours, rather than changes in broader skills, such as communication as a whole.