Discrete trial training (DTT) is a teaching modality that involves breaking larger skills into smaller components. DTT has three distinct parts:
- Antecedent: the trainer’s presentation.
- Behaviour: the student’s response.
- Consequence.
DTT facilitates the development of a new skill by simplifying the task and providing opportunities to practice while getting reinforcement for the correct answer.
In DTT we begin by teaching a single item using prompting and reinforcing the correct answers until the learner demonstrates the ability to perform the new skill.
We might teach colours beginning with red. We would ask the student to point to red, provide a prompt if needed, and then reinforce the behaviour (we call this Mass Trials). We would then move on to teaching yellow and reinforce that skill. Once both colours are mastered when presented alone, we then ask the student to point to either red or yellow when the trials are mixed (we call this Random Rotation). After the student learns to point to a variety of colours when trials are mixed, we may teach the student to say each colour’s name. (Pratt & Stewart, 2018)
During DTT data is taken from the learner´s response so that the teacher can determine when a new skill is mastered. DTT is effective in teaching skills such as following instructions, matching, identification and naming objects and pictures. It is not recommended for teaching communication or social skills.
The model looks like this (Lizard Centre, 2017):
Because individuals with autism learn best through repetition, this is a direct and intentional teaching strategy that many professionals should use. DTT programmes usually involve several hours, months or even years of discreet trials. The advantages that training in discrete trials can have include:
- Skills are broken into discrete components that are easier for students with autism to learn.
- The short trials maximise the student’s chances to complete tasks successfully and provide many opportunities for reinforcement. (Prat & Steward, 2018)
While it is a useful training tool, there are disadvantages to only using discrete trial training. In general, people with autism excel at memorization and unfortunately memorisation is often confused with true understanding or comprehension.
People with autism also have difficulties with generalisation. If mass trials are provided using the same materials, the same phrases and in the same environment, specialists cannot be convinced that the learner will be able to practice the skill or retrieve the knowledge with new materials and in new environments. Generalisation and real-world use should always be intentionally scheduled within DTT programmes.
Ultimately, the achievement of any strategy can be measured by how well learners perform a skill in non-instructional contexts. This should be addressed in the early stages of any programme.
The steps to follow when implementing this methodology with a person with autism are attached as Annex 1 (Bogin et al 2010).