We are developing a Web-based programming education support tool pgtracer as a plug-in of well-known Learning Management System Moodle. Pgtracer provides fill-in-the-blank questions composed of a C++ program and a trace table to students. When a student answers a question by filling the blanks, pgtracer collects student's answers, required time, evaluation result, etc. as student log. Pgtracer also provides various analysis functions of the collected log. A teacher can utilize the analysis functions in order to analyze the student achievement level and the difficulty level of the problems. In this paper, we propose methods to analyze achievement level of the students utilizing the analysis functions. We perform an evaluation experiment with 50 students in order to validate those methods. As a result, difference was discovered at the answer process caused by the achievement level of the student. The proposed method is useful to analyze achievement level of the students in detail.