(2) col. 2, ln 30 - col. 3, ln 9 - One feature of the invention involves a method for displaying the results of a multiple-category search according to levels of significance of the categories to a user's search query. The method can be used to display the results of a search for products or for any other type of item. In a preferred embodiment, the method involves receiving a search query from a user and identifying, within each of multiple item categories, a set of items that satisfy the query. The sets of items are then used to generate, for each of the multiple categories, a score that indicates a level significance or relevance of the category to the search. The scores may be based, for example, on the number of hits (items satisfying the query) within each category relative to the total number of items in that category, the popularity levels of items that satisfy the query, or a combination thereof. The categories and associated items are then presented to the user in a display order that depends upon the scores--preferably from highest-to-lowest significance. Other significance criteria, such as a category preference profile of the user, may additionally be used to select the display order. In addition, other display methods for highlighting the most highly ranked categories may additionally or alternatively be used. The method increases the likelihood that the categories that are of most interest to the user will be presented near the top of the search results listing, or otherwise called to the attention of the user. To assist the user in efficiently viewing a cross section of the located items and their categories, no more that N items (e.g., the most highly ranked three items) within each category are preferably displayed on the initial search results page. Another feature of the invention involves a system and methods for assisting users in locating web sites or pages from which user-specified products can be purchased. In a preferred embodiment, each web page located by a crawler program is initially evaluated, according to a set of content-based rules, to generate a score that indicates a likelihood that the web page includes a product offering. The scores may additionally be based on other criteria, such as the content of other web pages of the same web site. Representations of some or all of the scored web pages are stored in a keyword index that maps keywords to addresses (URLs) of the web pages. The keyword index is used by a query server to locate web pages that are both relevant to a user's search query and likely to include a product offering. This may be accomplished, for example, by limiting a scope of the search to web pages having a score that satisfies a particular threshold.