TY - JOUR T1 - Computerized adaptive testing with multiple-form structures JF - Applied Psychological Measurement Y1 - 2004 A1 - Armstrong, R. D. A1 - Jones, D. H. A1 - Koppel, N. B. A1 - Pashley, P. J. KW - computerized adaptive testing KW - Law School Admission Test KW - multiple-form structure KW - testlets AB - A multiple-form structure (MFS) is an ordered collection or network of testlets (i.e., sets of items). An examinee's progression through the network of testlets is dictated by the correctness of an examinee's answers, thereby adapting the test to his or her trait level. The collection of paths through the network yields the set of all possible test forms, allowing test specialists the opportunity to review them before they are administered. Also, limiting the exposure of an individual MFS to a specific period of time can enhance test security. This article provides an overview of methods that have been developed to generate parallel MFSs. The approach is applied to the assembly of an experimental computerized Law School Admission Test (LSAT). (PsycINFO Database Record (c) 2007 APA, all rights reserved) PB - Sage Publications: US VL - 28 SN - 0146-6216 (Print) ER - TY - JOUR T1 - Lagrangian relaxation for constrained curve-fitting with binary variables: Applications in educational testing JF - Dissertation Abstracts International Section A: Humanities and Social Sciences Y1 - 2000 A1 - Koppel, N. B. KW - Analysis KW - Educational Measurement KW - Mathematical Modeling KW - Statistical AB - This dissertation offers a mathematical programming approach to curve fitting with binary variables. Various Lagrangian Relaxation (LR) techniques are applied to constrained curve fitting. Applications in educational testing with respect to test assembly are utilized. In particular, techniques are applied to both static exams (i.e. conventional paper-and-pencil (P&P)) and adaptive exams (i.e. a hybrid computerized adaptive test (CAT) called a multiple-forms structure (MFS)). This dissertation focuses on the development of mathematical models to represent these test assembly problems as constrained curve-fitting problems with binary variables and solution techniques for the test development. Mathematical programming techniques are used to generate parallel test forms with item characteristics based on item response theory. A binary variable is used to represent whether or not an item is present on a form. The problem of creating a test form is modeled as a network flow problem with additional constraints. In order to meet the target information and the test characteristic curves, a Lagrangian relaxation heuristic is applied to the problem. The Lagrangian approach works by multiplying the constraint by a "Lagrange multiplier" and adding it to the objective. By systematically varying the multiplier, the test form curves approach the targets. This dissertation explores modifications to Lagrangian Relaxation as it is applied to the classical paper-and-pencil exams. For the P&P exams, LR techniques are also utilized to include additional practical constraints to the network problem, which limit the item selection. An MFS is a type of a computerized adaptive test. It is a hybrid of a standard CAT and a P&P exam. The concept of an MFS will be introduced in this dissertation, as well as, the application of LR as it is applied to constructing parallel MFSs. The approach is applied to the Law School Admission Test for the assembly of the conventional P&P test as well as an experimental computerized test using MFSs. (PsycINFO Database Record (c) 2005 APA ) VL - 61 ER -