Abstract
The more recent interpretation of triangulation in social and educational research was summarised and examined with reference to theory triangulation applied in an empirical study. The construction of special educational needs (SEN) from the individual experiences of a sample of SEN co‐ordinators and SEN teachers, parents, and adolescents with emotional and behavioural difficulties or physical disabilities were interpreted from the perspectives of personal construct theory, bio‐psycho‐social model, socio‐psychological analysis, bioecological model of human development and a developmental model of self‐understanding. Their points of convergence and divergence enriched and extended theoretical understanding. The focus on the ‘verstehen’ psychological level of analysis and on forging closer theory, concept and data connections influenced the range of theory choice. This instance of theory triangulation casts doubts on the Duhem‐Quine thesis of underdetermination.