Querying Instances - A Protocol Analysis Study

The instance-based paradigm - introduced as an alternative to traditional class-based database management methods - does not require imposing a well-defined schema over data, nor does it entail central control and planning. As a consequence, it supports information requirements agility, enables collection of higher quality data, and reduces the schema and database operation problems associated with traditional methods. This study investigates the ability of content-consumers to use instance-based representations effectively for information retrieval purposes. A visual representation of the instance-based data was created and empirically evaluated with 12 subjects using protocol analysis. Results show that instance-based users were able to retrieve the required information more accurately compared to users of the traditional representation. From a cognitive point of view, instance-based users were more efficient than class-based users - they experienced fewer breakdowns in their problem solving process and, when breakdowns occurred, were more successful in recovering from them.