Discrete trial training (DTT) is a highly-structured training technique that involves a trainer instructing an individual on the autism spectrum using a series of learning opportunities or ‘trials’. Each ‘trial’ has a definite beginning and end, which is why they are described as ‘discrete’.
The trainer begins each trial with a short, clear instruction or a question. The trainer may also prompt the learner, showing him how to respond correctly to the instruction or question.
If the learner does what the trainer wants, she will immediately reward him. For example, she may praise him or allow him to have something he wants or likes. If the learner does not do what the trainer wants, she will repeat the instruction or try a slightly different approach.
DTT is the main (but not the only) strategy used to teach children on the autism spectrum in early intensive behavioural interventions based on applied behaviour analysis, such as the UCLA YAP Model.
DTT can be a useful procedure for very specific targeted behaviours or skills as part of a broader programme of intervention. However, if it is seen as an end in its own right, it is unlikely to produce lasting benefits (for example, by not actively teaching skills that can be used in situations or settings outside of the training session).
Future research should use randomised controlled designs to investigate the effectiveness of DTT against active control groups (for example, by directly comparing DTT with other interventions, relative to a no-treatment control group) using larger sample sizes.
It would also be helpful to identify the effectiveness of DTT, where DTT is a part of a wider programme, investigating whether and how DTT adds value to the programme (for example, are there particular skills that are more receptive to being taught using DTT techniques than others).
It would be helpful to examine the efficacy and any side effects of DTT on the autistic participants, such as stress or self-injurious behaviour, and over a much longer period.
Any future research should also involve people on the autism spectrum to review the efficacy and ethical basis of discrete trial training including individuals who may be non-verbal.
Please read our Disclaimer on Autism Interventions