Resource discovery services for digital library have evolved significantly. There is an increasing use of dynamic user interface. New ways of user interactions are also emerging. Faceted searching for example provides a “navigational metaphor” for boolean search operations. It also results in greater user satisfaction (Olson 2007). AquaBrowser is a leading library product which provides faceted searching and new resource discovery features based on emerging interaction design patterns ('fresh, modern interface' according SerialsSolutions). These features appear to support better ways of searching: fast drill-down of results, enhanced search context.
An interaction design pattern we explored earlier this year, through a UX2.0 study (heuristic inspection) is the "Word Cloud" feature which according to SerialsSolution provides context-sensitive exploration. The unique UI is essentially a composite design pattern based on word (tag) cloud and spatial navigation - a term coined by the Nielsen Norman Group. AquaBrowser's tag cloud is unique as it does not utilise the typical size effect and rely on colours showing different types of word association. It also uses spatial navigation in combinant - tags move or reorganising during user interactions. Despite its popularity, the use of tag cloud even in its most basic form, remains contentious and nascent at least from usability perspectives. A recent statement from the Nielsen Norman Usability Week has urged sites to use tag cloud with caution and certainly not to use it for mainstream purposes. Furthermore this technique may either become a standard design or expire in a few years. On the contrary, recent studies on AquaBrowser have confounded the usual dismissive views of word cloud, suggesting potential for serendipitous discovery even for domain experts (Olson 2007). Moreover, word cloud has been an active subject in digital library research and development, e.g. as a visualisation device to gauge content relevance 'as a glance' (Gottron 2009).
