Hoerger, MaggieAlsuwayhiri, Bashaer Muthyib D2026-03-012025https://hdl.handle.net/20.500.14154/78349Applied Behaviour Analysis (ABA) is increasingly used in the United Kingdom across education, health, and social care. However, the regulation of practitioner competence remains underdeveloped. Following the withdrawal of international credentialing by the U.S.-based BACB in 2023, the UK Society for Behaviour Analysis (UK-SBA) introduced a national Competence Framework. The central research question of this study was: Does the UK-SBA Competence Framework accurately reflect the skills required for the competent, safe, and ethical practice of behaviour analysis in the UK? This qualitative study employed the Critical Incident Technique (CIT) to collect detailed accounts from practising behaviour analysts. Participants described specific incidents in which their competence was tested, with narratives explicitly linked to domains of the UK-SBA framework. Semi-structured interviews were conducted, and data were analysed using Braun and Clarke’s six-phase Thematic Analysis. Ethical approval was secured, with informed consent, anonymity, and data protection strictly observed. Findings revealed five key domains of practice: collaboration and communication, assessment rationale and planning, professional boundaries, scope and supervision, and generalisation strategies. Competent practices were characterised by openness, shared decision-making, cultural sensitivity, and reflective supervision, whereas non-competent practices involved exclusion of stakeholders, rigid or jargon-heavy approaches, blurred role boundaries, scope violations, and weak supervision. The findings indicate that, although the UK-SBA framework represents a robust technical and ethical framework, it fails to adequately represent other linked competencies considered key by practitioners, such as relational and cultural skills and supervisory skills, which are identified as being central to safer and more effective work. The research has implication to training, supervision, regulatory refinement, and suggests further incorporation of interpersonal, contextual, and client-centred skills to national standards.79enUK-SBACompetence FrameworkUK-SBA Competence FrameworkBehaviour Analystspractitioner competenceBACBCritical Incident TechniqueCITCompetent practicesnon-competent practicesThesis