A framework for expressing and combining preferences

Abstract

The advent of the World Wide Web has created an explosion in the available on-line information. As the range of potential choices expand, the time and effort required to sort through them also expands. We propose a formal framework for expressing and combining user preferences to address this problem. Preferences can be used to focus search queries and to order the search results. A preference is expressed by the user for an entity which is described by a set of named fields; each field can take on values from a certain type. The * symbol may be used to match any element of that type. A set of preferences can be combined using a generic combine operator which is instantiated with a value function, thus providing a great deal of flexibility. Same preferences can be combined in more than one way and a combination of preferences yields another preference thus providing the closure property. We demonstrate the power of our framework by illustrating how a currently popular personalization system and a real-life application can be realized as special cases of our framework. We also discuss implementation of the framework in a relational setting.

Research Directions of OLAP Personalizaton

“…Although the role of the preferences was recognized in applications long ago, the database researchers paid attention to this issue only around year 2000 [17,18,19,20]. It was observed that in database queries WHERE-conditions are hard constraints and either the non-empty result set is returned if all the conditions are satisfied, or an empty set is returned in the opposite case.…”

Querying the Semantic Web with Preferences

“…In quantitative approaches, each preference is associated with an atomic scoring function, and combination operations are used to compute a score for each result tuple [12]. This restricts the approach to total orderings of result tuples.…”

Efficient Approximation of Optimization Queries Under Parametric Aggregation Constraints

“…Indeed, over the years, several proposals enhancing the query capabilities of relational systems have been made. Recent examples include preference queries, which incorporate qualitative and quantitative user preferences [1,3,13,8,17] and topqueries [10,9,2].…”

“…Such queries are introduced as a novel query type seeking to provide greater query flexibility on top of relational data sources. Recently proposed, but not directly related, query types include preference queries [1,12,3,13,8,17] and top-k queries [10,9,2].…”