A method for designing IRT-based item banks

Since 1985 several procedures for computerized test construction using linear programming techniques have been described in the literature. To apply these procedures successfully, suitable item banks are needed. The problem of designing item banks based on item response theory (IRT) is addressed. A procedure is presented that determines whether an existing item bank meets the test construction requirements. If not, the method indicates which items have to be added to the banks so that it will meet the requirements. The comparison of desired and present item bank characteristics, writing, and calibrating items continues until the characteristics of the item bank are acceptable. Four categories of characteristics are: (1) general characteristics (such as format); (2) subject matter characteristics (such as learning objective); (3) psychometric characteristics (such as IRT-parameters); and (4) user statistics. One figure illustrates the procedure.