Informal environments such as museums and science centres are important learning arenas, but research has yet to address the problem of how to optimise
the relationship between the learning environment – the exhibition – and the learner. This paper suggests a design tool which addresses a problem known to occur in the meeting between exhibit and learner but which also provides a concrete
method for developing an exhibit or exhibition in a museum ontext. The tool, developed from the notion of praxeology (Chevallard, 1999), may be used descriptively for the analysis of existing exhibits, or prescriptively in the design of new exhibits. These uses of the tool are illustrated in the paper.