A defining feature of PRT is its focus on “pivotal” areas or responses that are alleged to underlie large collateral changes in other areas of functioning. Thus, PRT addresses generalisation, a skill which has consistently been found to pose difficulties for people on the autism spectrum. Because the intervention is designed to produce widespread improvement in other areas, PRT is more efficient than Discrete Trial Training which gives priority to isolated individual behaviours and typically requires intensive and expensive training of about 40 hours a week.