Increased usage of Web search engines in our daily lives means that the trustworthiness of searched results has become crucial. User studies on the usage of search engines and analysis of the factors used to determine trust that users have in search results are described in this paper. Based on the analysis, we developed a system to help users determine the trustworthiness of Web search results by computing and showing each returned page’s topic majority, topic coverage, locality of supporting pages (i.e., pages linked to each search result) and other information. The measures proposed in the paper can be applied to the search of Web-based libraries or can be useful in the usage of digital library search systems.