This work attempts to explore the methodological legacy of George Kelly – repertory grid analysis – as an aid to visually mapping the structures of students’ concepts. Although, Kelly formulated a complex Euclidian framework of psychological laws, axioms, and corollaries, we have concentrated on the methods that later workers took from Kelly’s original ‘RepGrid Test’. The central entity is a self-constructed concept, or set thereof, that may be represented in a matrix. As a matrix of integers can be manipulated by a large variety of statistical protocols, we explore in three studies how such matrices may be derived in relation to students` concepts of living kinds, and then how they may be analysed. Typcially, we use principal components analysis – a model-free form of factor analysis. The resultant loadings derived from these analyses are plotted on Cartesian planes from which additional information about the structure of the students’ conceptualizations may be derived.