Abstract
Identifying the interests of client groups is obviously vital for good planning. Yet, the accurate identification of people's interests, especially in relation to “quality-of-life” issues, involves complex judgments; mistaken judgements of interest are therefore always likely. This paper explores this problem by clarifying the different kinds of mistaken interest judgements we can make and discussing how such mistakes may be minimized in relation to planning. The suggestions presented for minimizing mistaken interest judgements—suggestions about rational deliberation and the collective discussion of interests—further support what I term the “discourse model” of planning, which has emerged in planning theory in recent years. The paper also draws some implications for the methodology of empirical research into people's interests, and concludes by connecting the discussion with the idea of deliberative democracy.