Subscores are often used to indicate test-takers' relative strengths and weaknesses and so help focus remediation. But a subscore is not worth reporting if it is too unreliable to believe or if it contains no information that is not already contained in the total score. It is possible, through the use of a simple linear equation provided in…

Subscores can be of diagnostic value for tests that cover multiple underlying traits. Some items require knowledge or ability that spans more than a single trait. It is thus natural for such items to be included on more than a single subscore. Subscores only have value if they are reliable enough to justify conclusions drawn from them and if they…

Discusses the comparison of groups of individuals who were administered different forms of a test. Focuses on the situation in which there is little overlap in content between the test forms. Reviews equating problems in national tests in Canada and Israel. (SLD)

Discusses regression toward the mean and the confusion this can cause in the interpretation of educational data. The regression effect has two causes, imperfect measurement of the variables and imperfect correlation between the variables. Uses the example of reading achievement test scores in a Hawaiian private school to illustrate the discussion.…

Some cautions are sounded for converting a linearly administered test to an adaptive format. Four areas are identified in which practices broadly used in traditionally constructed tests can have adverse effects if thoughtlessly adopted when a test is administered in an adaptive mode. (SLD)