01754nas a2200217   4500008004100000245015600041210006900197300001100266490000600277520090700283653004001190653002201230653002401252653002301276653003701299653001001336653002401346653002701370100001801397856012101415       1998                        eng d00aThe effect of item pool restriction on the precision of ability measurement for a Rasch-based CAT: comparisons to traditional fixed length examinations0 aeffect of item pool restriction on the precision of ability meas  a97-1220 v23 aThis paper describes a method for examining the precision of a computerized adaptive test with a limited item pool. Standard errors of measurement ascertained in the testing of simulees with a CAT using a restricted pool were compared to the results obtained in a live paper-and-pencil achievement testing of 4494 nursing students on four versions of an examination of calculations of drug administration. CAT measures of precision were considered when the simulated examine pools were uniform and normal. Precision indices were also considered in terms of the number of CAT items required to reach the precision of the traditional tests. Results suggest that regardless of the size of the item pool, CAT provides greater precision in measurement with a smaller number of items administered even when the choice of items is limited but fails to achieve equiprecision along the entire ability continuum.10a*Decision Making, Computer-Assisted10aComparative Study10aComputer Simulation10aEducation, Nursing10aEducational Measurement/*methods10aHuman10aModels, Statistical10aPsychometrics/*methods1 aHalkitis, P N  uhttp://mail.iacat.org/content/effect-item-pool-restriction-precision-ability-measurement-rasch-based-cat-comparisons