Research On Design And Implementation Of Computer Aid Instruction Environment

Test is the last and vital part of teaching process. We are trying to seek for an effective approach on students' capacities: "different approaches on different testees". This paper discusses how to take adapter tests on students' capacities through computers.Firstly, we elucidates the basic principles and typical applications of Item Response Theory (IRT), taking the theory of IRT as a basic theory of Computer Adapter Test (CAT).Then we presents a new Parameter Evaluation Algorithm(PEA) taking account of the value of item capacity, based on IRT and Parameter Evaluation Algorithm. The algorithm can calculate the capacity value needed to answer the testing item correctly through recording the status of item extracted, according to the importance of knowledge point examined and the difficulties evaluated by examinant. Lastly the real evaluation value of capacity can be acquired by ascertaining corresponding parameters through utilizing above information.Finally, we designs and implements a practical computer adapter teaching environment-CAT system including integrate testing modules, such as extracting test paper, maintaining the testees's information, managing the database of testing items and etc. It is proved that this system can choose corresponding examination questions according to testees' capacities and test effectively, fulfilling objective evaluation on testees accordingly.