Requirement analysis for web applications still needs to employ effective RE practices to accommodate some distinctive aspects: capturing high-level communication goals, considering several user profiles, defining hypermedia-specific requirements, and reusing requirements for an effective usability evaluation. Techniques should be usable, informal, require little training effort, and show relative advantage to project managers. Starting from the i* framework, this paper presents a proposal for defining hypermedia requirements (concerning aspects such as content, navigation and presentation) for web applications. The model adopts a goal-driven approach coupled with scenario-based techniques, introduces a hypermedia requirement taxonomy to facilitate web conceptual design, and paves the way for systematic usability evaluation. Particular attention is paid to the empirical validation of the model based on the perceived quality attributes theory. A case study developed with industrial partners is discussed.