ABSTRACT

In practice, (test) data for a specific examinee can be limited. A teacher or psychologists might be interested, for instance, in estimating the math ability of a specific examinee, but the scope of the math test the examinee completed is limited. Or, the teacher or psychologist might be interested in the question of how reliable the examinee’s score is on the test (i.e., the error variance), but the examinee did not answer enough items or tests to accurately estimate this reliability. In such cases, it can be beneficial to supplement the information from the single examinee with other information sources. This chapter explores two such sources. The first is the rich but often ignored source of teacher knowledge. The second is the possibility of using test results of more or less ‘similar’ examinees (e.g., examinees with the same or comparable test scores). This chapter discusses how teacher knowledge and test results of ‘similar’ examinees can be used to improve the estimation of an examinee’s math ability.