A broad-range tailored test of verbal ability

Two parallel forms of a broad-range tailored test of verbal ability have been built. The test is appropriate from fifth grade through graduate school. Simulated test administrations indicate that the 25-item tailored test is at least as good as a comparable 50-item conventional test. At most ability levels, the tailored test measures much better. An offer is made to provide upon request item characteristic curve parameters for 690 widely used Cooperative Test items, in order to facilitate research.Lord, Frederic M.. (1977). A broad-range tailored test of verbal ability. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/98423

Standard error of an equating by item response theory

A formula is derived for the asymptotic standard error of a true-score equating by item response theory. The equating method is applicable when the two tests to be equated are administered to different groups along with an anchor test. Numerical standard errors are shown for an actual equating (1) comparing the standard errors of IRT, linear, e and equipercentile methods and (2) illustrating the effect of the length of the anchor test on the standard error of the equating