Human-Computer Interaction (HCI) has gathered many guidelines for interface design and has dis- covered the strengths of direct manipulation as an interaction technique. However, to date it has been generally assumed that these guidelines apply generically across all applications. In this paper I intend to challenge this assumption in relation to educational software.
First I shall consider why educational software is different from other products, such as databases or word-processors, before presenting a variety of evi dence that suggests that designing for learning might be harder than designing for use - our guide lines are good for optimising current performance, not future performance.
The experiments to be presented will show how good performance can be associated with low rates of transfer, how poor initial performance can give rise to more robust knowledge for harder problems and how command giving rather than direct action may produce better learning.
A full psychological explanation is still needed, but one can speculate that
a. interfaces which encourage planning, rather than situated action may produce better learning.
b. in so far as direct manipulation may be beneficial, it is not by providing direct manipulation of the interface components.
c. the learner needs a sense of engagement with the learning materials, not the interface.