A method that enables a tester to efficiently perform confirmation behavior of a Web page that utilizes DHTML or difference in behavior of the Web page among various browsers, or assignment of information relating to accessibility of the Web page or verification of the information. A method is provided that analyzes change in a Web page by determining states that can dynamically occur in response to an external event in a Web page that utilizes DHTML by analyzing at least one of DOM, style information for when rendered on a browser, input data from a user, and the value of a global variable in JAVA®SCRIPT, storing data that can identify each of the states, identifying state transition between the stored states, and reproducing the stored states.