Due to the development of Web technology and interdependency between organizations and customers, organizations are using Web sites as a mechanism to enable and facilitate knowledge acquisition (KA). A user can acquire knowledge that a sponsor offers via a Web site. Conversely, s sponsor can acquire knowledge that a user offers via a Web site. This paper introduces a set of propositions that can underlie efforts to develop a KA framework for guiding and studying Web site design. The propositions identify four major elements (user features, sponsor features, system features, and environmental features) as the main determinants of a Web site’s usability for KA.