'Repertory grid analysis 'was used as a way of constructing representations of learners conceptions of living things; and finding a common structure or understanding; this was described in previous work. 'Concept mapping ' has been stated as an appropriate assessment procedure in science curricula in a number of countries. Previous relevant published work describing the benefits of 'concept mapping' as a learning, teaching, and assessing tool is large. However, the existence of a large literature is not justification in itself, and in this work we provide a critique of the current literature. Problems with 'concept mapping 'are simply ignored. However, it is thought that 'repertory grid analysis 'does overcome some of the recognized problems of 'concept mapping' such as; i) comparison of concept maps between students or between students and educators; in repertory grid this becomes not only possible but a reliable method - this has proven to be one of the more problematic areas in traditional 'concept mapping'; ii) quantification of concept mapping - integer scoring of whole concept maps in 'repertory grid analysis ' is eliminated since the arranged structure of the graph produced holds significance for the conceptual structure. More research needs tobe done in repertory grid analysis and its implications and applications In curricular research have yet to be fully explored.