How to take into account a student´s degree of certainty when evaluating the test results

To more adequately gauge the student´s knowledge, it is desirable to take into account not only whether the student´s answers on the test are correct or nor, but also how confident the students are in their answers. For example, a situation when a student gives a wrong answer, but understands his/her lack of knowledge on this topic, is not as harmful as the situation when the student is absolutely confident in his/her wrong answer. In this paper, we use the general decision making theory to describe the best way to take into account the student´s degree of certainty when evaluating the test results.