Three empirical studies investigated equivalence based instruction (EBI) as a method of teaching categorisation to young children (3-6 years). In empirical Chapters 2-4 six conditional discriminations were training using a touch screen matching-tosample (MTS) programme and tested for emergence of three derived (untrained) threemember classes. Chapter 2, Experiment 1 successfully tested EBI, modified MTS procedure with neurotypical children and findings were replicated in Experiment 2 with children with Autistic Spectrum Disorder. Chapter 3 compared the efficacy of the EBI, modified MTS procedure with a traditional teaching aspect. In terms of direct teaching time no significant differences were demonstrated indicating that the EBI procedure may have application in mainstream educational settings. Chapter 4 investigated if EBI is effective to teach generic skills (Irish Primary Curriculum), and examined group contingencies across three experiment which took place within two mainstream educational settings with slightly older populations (5-7 years). Using an electronic student response system, individual and group data were recorded per trial. Significant differences were found between pre and post intervention category knowledge. The findings overall provide support for EBI to teach simple and complex category membership using group contingencies in traditional education settings. Additions to the literatures include the first known comparison of equivalence based instruction (EBI) with another established method for teaching categorisation (Chapter 3). Chapter 4 provided the first known study to combine EBI with existing technologies to examine group contingencies.