A Framework for Navigation
Bob Spence,
Imperial College, London, England
INTRODUCTION
For more than two decades I have observed myself and others using terms such as navigation and browsing rather loosely, albeit to refer to important concepts. I have therefore tried to clarify these terms and, in so doing, have proposed a framework that might well support organised thought about navigation and related matters [1]. I have done so from the point of view of an interaction designer with a background in engineering.
I have suggested that navigation broadly comprises four activities: strategy formulation, browsing, context modelling and gradient perception. Traversal of these activities will often be cyclic, as illustrated in Figure 1, and almost always iterative; more detail will appear in Figure 4.
I define browsing to be the assessment of content. Often - though not necessarily - achieved visually and rapidly according to some formulated strategyof viewing displayed data, it answers the question "what's there?". There is no specific target being sought, though there may well be weights associated subjectively with possible item types. Browsing allows the modelling of context, providing some sort of 'map' which may facilitate beneficial movement in 'information space'. The availability of a context model allows gradient perception , typically leading to a decision to alter the browsing scheme, perhaps to determine the 'best' direction in which to move in information space towards a goal. Traversal of this sequence of activities constitutes the navigational process., a process which will be governed by some higher level intention. The simple model of Figure 1 will now be explained, and supported by the Strategy-Browse-Context-Perception model of Figure 4.