Existing research on context and context awareness has broadly focused on the technical aspects of context acquisition and interpretation of users' surroundings, also called physical or sensor-based context. Such an approach has lacked from reconciling the perception of real-world context exhibited by humans, also known as user context, and context-aware systems' interpretation of that context. This dissertation research contributes to the current understanding of the role of the user context in the acquisition and presentation of context information. In particular, it proposes a novel approach to representing the user contextual information in defining the overall value of context awareness, by coupling physical context with user situational context information. An operational mechanism for incorporating user context in the design and development of context-aware systems is developed and evaluated based on the proposed approach. The first part of the dissertation work explores how to extract the four primary types of context information defined in the literature; location, time, identity, and activity, from the user situational context. The research presents an empirical validation of a user-centered context awareness approach which brings users' needs and context-aware systems' acquisition of context information closer based on the relevancy of users' situational context. The proposed approach reduces the complexity of traditional approaches to user context acquisition and interpretation by leveraging users' interactional dialogue with their personal computing artifacts. The research results suggest that it is possible and beneficial to incorporate user situational context into context-aware system design and development. The second part of the dissertation focuses on evaluating the added value of incorporating users' situational context in defining the overall value of context awareness. Based on the results, a comprehensive and integrated framework that accounts for both user and physical context in defining an overall context awareness value is proposed. The research offers tangible help to context-aware designers who may not be acquaint with tools effective for designing and developing integrated context awareness information requirements. The dissertation has several theoretical contributions and practical implications. First, the dissertation attempts to fill the void of ignoring the entangled relationship between the physical and user context. The work proposes a new schema for context acquisition and presentation that takes into account the relevant dependency between users' activities and their surrounding context. Second, the dissertation has important implications for decision support that involves data filtering and focus. In today's pervasive computing environment, data relevant to context-aware decision support systems can originate from many, sometimes conflicting, sources. The results of this research can be used to filter and select data pertinent to inclusion within context-aware decision support systems. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]