Evaluating natural areas using multiple criteria: Theory and practice

Abstract

Evaluating natural areas involves making measurements for a series of criteria and deciding which areas are most significant based on these measurements. We review the basic theory of measurement and its application to assessing criteria in 20 different conservation evaluation studies. Different types of models exist to assess the overall significance of natural areas based on multiple criteria. A brief description is presented of these “multicriteria evaluation models” and the underlying theory. The assumptions of these models are outlined as are the types of information that are appropriate to each. We then examine how a final overall ranking is derived in the 20 studies. None explicitly stated the model used and few noted the assumptions involved. Based on theory and current practice, a number of principles are presented to guide the development of evaluation methods. We conclude that evaluation methods should not be allowed to cloud important issues or conceal value judgements. Furthermore, the assumptions of any evaluation method should be clearly stated and rationalized in terms of the data and areas being compared.