A framework is proposed for the systematic application of objective knowledge to the solution of practical problems in mounting didactic exhibits. It brings together aspects of educational technology and observations on the behaviour of visitors in museums, to form a museum technology. This has a common basis with educational technology in the nature of the learning process, but as educational institutions, museums are distinguished by their informality and by the heterogeneity of their learners. Attraction and holding are valuable measures of exhibit effectiveness; a new model is developed to sharpen and extend the applicability of these concepts. The practical value of museum technology is summarized in a series of precepts for the design of effective exhibits. These form two sets; the first is derived from observational studies and concerns architectural factors, the second is based on selected aspects of educational technology.