Applications of Uniform Test Assembly for the LSAT (RR 05-01) (PDF)

The Law School Admission Council (LSAC) is a nonprofit corporation whose members are more than 200 law schools in the United States and Canada. It was founded in 1947 to coordinate, facilitate, and enhance the law school admission process. The organization also provides programs and services related to legal education. All law schools approved by the American Bar Association (ABA) are LSAC members. Canadian law schools recognized by a provincial or territorial law society or government agency are also included in the voting membership of the Council. This study is published and distributed by the Law School Admission Council (LSAC). The opinions and conclusions contained in these reports are those of the authors and do not necessarily reflect the position or policy of the Law School Admission Council. In a large-scaled high-stakes testing program such as the Law School Admission Test (LSAT), it is necessary to maintain a large bank of test items to support the demand for a new test form at nearly every administration. To assure that the item bank can support the test assembly requirements, ongoing monitoring of the quality of the item bank is necessary to identify deficiencies and direct item development efforts. Recent research along these lines has included efforts to identify the properties of the most valuable item in the item pool, identify the test assembly constraint(s) that are the most difficult to meet, determine the distribution of test taker ability that supports the highest degree of usability of the item pool, and develop statistical test assembly targets for multiple stage testing. Many of these practical testing problems have recently been addressed by the application of test sampling methods. Test sampling may be described as the sequential assembly of multiple test forms such that each question (item) or item set can be used an unlimited number of times. Therefore, test forms produced can overlap with each other, i.e., have items/item sets in common. The result is a sample of test forms from the finite set of all test forms available from the given item pool under a given set of test assembly constraints. In order to insure that the inferences from such research are statistically correct, the sampling must be uniform, that is, each test should have an equal chance of being assembled. Thus, the test assembly problem plays a fundamental role in the test sampling method. In particular, our interest is in methods …