Theoretical Considerations on Applying Analytic Hierarchy Process to Evaluation Process

In the evaluation process of the District Suitability Classification (DSC), an empirical method or Principal Component Analysis (PCA) method have been applied for identifying an evaluation function. In this paper, the authors propose a new evaluation method by Analytic Hierarchy Process (AHP), which was recently developed by T. L. Saaty. Characteristics of the AHP method is theoretically compared with those of the former methods, viz; the empirical method and the PCA method. Some application problems are also discussed.The AHP method is, one side, in common with the empirical method in point that the norm of the evaluation function is given by subjective judgements of intellectuals and researchers. Because a style of subjective judgements of the AHP method is pair-wise comparison among indices, the weight coefficients estimated by the AHP method can be more accute than those by the empirical method. The other side, procedure of the AHP method is objective same as the PCA method. This means reappearance of the coefficients is assured. Because the AHP method has respective advantages of the former methods, it is thought that this method has a great possibility as a new evaluation method for the DSC.But it is not reasonable to fix the scale values of the AHP method, which translate pair-wise judgements to weight ratios. The scale values should be readjusted by each cases.