The first step of most information systems design m ethodologies consists in eliciting part of the user requirements from various sources such as user inte rviews and corporate documents. Regarding the core of the information system, that is, the database, t hese requirements are formalised into a conceptual schema of the application domain. Despite the intui tiveness and expressiveness qualities of conceptual formalisms, conceptual schemas have proved difficul t to validate due to understandability limitations from the end-users standpoint. On the contrary, ele ctronic forms are known to be a natural and intuiti ve way to express data requirements for laymen. Besides , the necessity to associate end-users of a future system with its specification and development steps has long been advocated. In this paper, we study data requirements elicitation techniques relying on user-drawn electronic forms. We explore the revers e engineering of form-based interfaces to perform an interactive database conceptual analysis, and subsequently present the tool-supported RAINBOW appro ach resulting from this investigation. This user-oriented approach relies on the adaptation and integration of principles and techniques coming from various fields of study, ranging from database forw ard and reverse engineering to prototyping and participatory design.