This paper starts from the assumption that any evaluation of educational software should focus on whether or not, and the extent to which, it maximizes learning. It is particularly concerned with the impact of software on the quality of learning. The paper reviews key texts in the literature on learning, including some which relate directly to software development, and suggests ways in which a range of learning theories can inform the process of software design. The paper sets out to make a contribution to both the design and the evaluation of educational software.