Development and evaluation of the question and answer system for core courses

Question and answer is indispensable as the beneficial supplement of teaching, especially for the core courses in universities because it is a great burden for a teacher to answer so many students in the class. The question and answer system based on network is developed to solve the above problem in this paper. Information conflict is inevitable for many students ask questions simultaneously during the system running. We use Petri net to model the solution of conflict, introduce multi-avatar structure to presents the question and answer process vividly and evaluate it with simulation to prove the validity of the system.