Although the interface can be viewed as a means to an end in terms of the project objectives, its design represents a major effort for the project. Some elements of configurability were incorporated in the design, but the choice of features to implement was limited by the nature of the operational test. For example the design had to cater for a short library catalogue record and a more extensive record incorporating abstracts in a uniform way. Another issue was to run the interface on both a UNIX workstation and a PC, where screen size and resolution are not compatible.
In evaluating a highly interactive system in a live setting, the control of experimental variables is a major problem. Prior formative evaluations can assist in separating out particular interface aspects from the underlying functionality, but there may be other undetected factors coming into play which can affect the usability and performance of the system being evaluated.