It is common for web searchers to have difficulties crafting queries to fulfill their information needs. Even when they provide a good query, users often find it challenging to evaluate the results of their web searches. Sources of these problems include the lack of support for query refinement, and the static nature of the list-based representations of web search results. To address these issues, we have developed WordBars, an interactive tool for web information retrieval. WordBars visually represents the frequencies of the terms found in the first 100 document surrogates returned from the initial query. This system allows the users to interactively re-sort the search results based on the frequencies of the selected terms within the document surrogates, as well as to add and remove terms from the query, generating a new set of search results. Examples illustrate how WordBars can provide valuable support for query refinement and search results exploration, both when specific and vague initial queries are provided.