The paper describes a teaching assistant facility being developed in Nippon Institute of Technology to activate question answering in computer programming practice using Web based teaching. The facility is implemented in the website to provide agent supported collaborative learning using community web software. The contents of the website are teaching materials for computer programming practice and an electronic bulletin board system for question answering to assist practice of the students. The students can send a question message to the bulletin board and then receive an answer message from the teacher or other students in the classroom. An agent in the website distributes the question message to teacher and/or the students being active to answer questions. The facility activates question answering between students as a form of collaborative learning.