The Comparison And Application Of MST Combined With CAT Testing

Nowadays, computerized adaptive test(CAT) is a very popular kind of test form. It based on the initial value of subjects’ ability select items automatically from the bank. When the subjects finish an item, computer will automatically estimate the ability of subjects at a time. Repeatedly, until the test reaches a certain predefined termination rules to stop. With its high measuring precision, CAT is favored by researchers. Testing time is relatively long for estimating subjects’ ability after every item. Compared with CAT, multistage testing(MST) can overcome this problem. MST is a kind of test forms based on computerized technology, consists of sets of items scored and administered as a unit(such as reading comprehension, diagram). This kind of test has many advantages, like less adaptation, fewer time, subjects can operate the items within the stage, etc. But its measurement precision is lower than CAT.Combined MST with CAT, a new test form is developed. In the early stage, using MST to estimate subjects’ ability roughly, and in the later stage use CAT to estimate subjects’ ability accurately. This test form effectively combines the advantage of MST and CAT, and overcome the disadvantage of the two. It effectively improve the test precision, and shorten the test time.In this research, compared the new test form with MST and CAT. Then applied it to the TIMSS grade eighth in the math test. Through simulation, the results of three test forms are compared. Simulation results show that:(1) from the point of test precision, CAT is the best, and the result of MST combined with CAT test is similar to CAT. MST is the worst.(2) From the point of test time, MST is the best, then MST combined with CAT test, the last is CAT. Empirical study results show that:(1) using MST combined with CAT test can measure the subjects’ ability value, and the results are basically obey normal distribution.(2) The validity of MST combined with CAT test used in TIMSS grade eighth in the math test is high.Thus it can be seen, MST combined with CAT test not only has good measuring precision, but also shorten test time. Therefore, this kind of test has a good prospect. Thus lay a good foundation to improve test quality, and also provides a good basis for better test forms. The direction of future research is to find better test forms, minimize measurement errors, and improve measurement precision, in order to make the application of test more convenient and effective.