Although research has shown a significant amount of work identifying various dimensions of relevance along with exhaustive lists of relevance criteria, there seem to have been less effort to apply the findings to improve actual systems design. Based on this assumption, this paper investigates to what extent those relevance criteria have been incorporated into the interface features of major commercial Web search engines, suggesting what can/should be done more. Before stepping into the actual system features, this paper compares recent relevance research in Information Science with other human factor studies both in Information Science and its neighboring discipline (HCI), as an attempt to identify studies that are conceptually similar to the relevance research, but not named as such way. Similarities and differences between these studies are presented. Recommendations suggested to support applicable interface features include: 1) further personalization of interface designs; 2) author-supplied meta tags for the Web contents; and 3) extensions of beyond-topical representations based on link structure.