Abstract: In the Web accessibility evaluation, the comprehensive value of the accessibility measurement reflects the accessibility of the Web. Existing research has shown that finding the right weight for different checkpoints is a challenging problem. Although some indicators derive checkpoint weights from WCAG 2.0 priorities, previous surveys have shown that WCAG 2.0 priorities are not significant related to the accessibility of the site’s accessibility, operability, comprehensibility, and robustness. In addition, the results of our website’s accessibility assessment also confirm that sites of using existing metrics do not match the four principles. In order to overcome this limitation, we propose a Web accessibility principle metric, which is called the Web Accessibility Principle Metric（WAPM）, so as to better match the evaluation results of the auxiliary function with the four principles, that is, using the analytic hierarchy process to analyze the four principles, because the association mapping between the detection point and the four principles is not exactly the case, we improve the analytic hierarchy process to derive the optimal detection point weights from the four principles. The actual website accessibility assessment data experiment verifies the effectiveness of WAPM.

Key words: four principles, accessibility indicators, accessibility criteria, analytic hierarchy process