So, search is a tool for information retrieval, but the transaction of searching encompasses more than just looking something up. With most commerce sites centered around a product catalogue, this tendency to navigate via search makes it more difficult to design a search system that meets the needs of all shoppers. Searching and Information Retrieval Expectations Lou Rosenfeld and Peter Morville devote several sections in their book Information Architecture for the World Wide Web to discussing the varying needs users bring to search. The user wants everything available on a given topic. Special Concerns With Searching a Product Catalogue Users tend to search for products with a different in mind than when they search against document collections.
Any meaning ascribed to the object is connotational.
In contrast, information in a document collection is more denotational. Any commerce site must study their customers and their market and develop a list of common user tasks. Users must be able to find products, and they must be able to follow paths appropriate to their own preferences.