nterventions based on applied behaviour analysis (ABA) have been demonstrated to be effective in teaching a range of skills to children with autism spectrum disorder (ASD) (Brett, Warnell, McConachie, Parr, 2016; Leaf et al., 2016). Interventions based on ABA can be comprehensive in that they target multiple areas of development; this type of intervention, known as a comprehensive model of education, is designed to have broad impact on the core deficits of ASD (National Research Council, 2001). Other interventions are more focused and address discrete behaviours; these are sometimes known as focused intervention practices (Dixon et al., 2016; Odom, Boyd, Hall, & Hume, 2010). Educational interventions for young children with ASD that are underpinned by the principles of ABA are related to best outcomes and considered ‘treatment as usual’ in Northern America (Keenan & Dillenburger, 2011). ABA is covered by medical insurance in at least fifty states in the USA and state educational and disabilities departments implement and fund interventions based on ABA (Autism Speaks, 2019). Early intensive behavioural intervention (EIBI) is also publicly funded in Norway (Eldevik, Titlestad, Aarlie & Tønnesen, 2019) and Canada. Conversely, intervention based on ABA are not typically delivered in maintained schools and other government funded settings in the United Kingdom (UK); instead, provision of this type of intervention is inadequate and uneven (North-Bates, 2016). The purpose of this thesis was to identify if interventions based on the science of ABA could be feasibly implemented in a maintained special educational needs (SEN) school in the UK. A comprehensive model of educational that delivered low intensity one-to-one teaching hours was developed with key stakeholders; this was evaluated with children with ASD. A number of focused intervention practices were adapted to make them more suitable for a SEN setting: a bespoke prompting procedure that is used during discrete trial training and interventions to decrease behaviours that are barriers to learning were also evaluated. All of the interventions were designed with contextual variables, such as typical SEN teacher to child ratios and limited resources in mind; it was essential that all of the interventions could the feasibly implemented in the setting. Chapter 1 begins with an introduction to the literature on comprehensive models of education for children with ASD. This overview will begin with traditional EIBI before reviewing some of the advancements to these models. Chapter 2 describesthe formulation phase on the British Early Special Schools Teaching (BESST) model of education. Thiswas a collaboration between university researchers, BCBA’s, teachers and other professionals to develop a comprehensive model of education that could be implemented in a special educational needs setting. Chapter 3 describesthe BESST model and presentsdata from aninitial evaluation of the model. Children made significant gains on standardised measures of intelligence quotient (IQ) and adaptive behaviour, and on a range of skills measured by Assessment of Basic Learning and Language Skills –Revisedâ(ABLLS-R; Partington, 2006). Chapter 5describes a bespoke prompting procedure, responsive prompt delay prompting procedure, that was implemented during discrete trial training (DTT) in the BESST model. This procedure was designed for this setting because we observed prior to conducting the research that commonly used procedures were difficult to implement with fidelity. The responsive prompt delay procedure was compared to simultaneous prompting and no-no prompting, two commonly used procedures. Results show that the responsive prompt delay procedure was as effective as the other procedures for three participants; efficiency data were variable. Chapter 7describes focused intervention practices that were developed for a SEN setting; SEN schools are busy clinical settings where many staff work with each child and as a result it can be difficult to control certain aspects of the environment. Data from two studies are presented. In the first study, an adapted functional analysis was conducted with two participants to verify that problem behaviour was maintained by a novel form of attention -predictable, repetitive statements. In the second study, data were presented from a treatment analysis that compared three function based interventions that wereintended to beimplemented without extinction. Extinction was not feasible because it was not possible to reduce predictable attention to zero levels in this setting. Functional communication training and non-contingent reinforcement reduced problem behaviour to near zero levels for both participants. Pre-session satiation did not decrease problem behaviour consistently. This thesis evaluated a comprehensive model of education and a number of focused intervention practices in a SEN school. All of the interventions were developed for this setting; a number of adaptations were necessary due to a range of contextual variables that presented challenges related to implementation. The comprehensive model of education based on ABA had a significant positive impact on a number of child outcomes. A bespoke prompting procedure that suited this setting was at least as effective as commonly used prompting procedures; and two interventions implemented reduced problem behaviours maintained by predictable repetitive statements. Interventions based on ABA were effectively adapted for this setting and resulted in positive outcomes for learners with ASD and other IDs.