A data-driven, hierarchical information search and navigation system and method enable search and navigation of sets of materials by certain common attributes that characterize the materials. A rules engine provides for manipulation of the content displayed to the user based on the query entered by the user. The rules engine includes one or more rules with a trigger and an action. The action of a rule is performed only if the trigger is satisfied. A trigger may be specified in terms of expressions of attribute-value pairs and is evaluated against a given query or navigation state. The actions can include various techniques for content manipulation, such as supplementing content, rendering content in a particular way, and sorting content in a particular way. An action may be specified in terms of navigation states. The rules engine may include a script for processing the rules.