The group did not have quite the same success with the equivalence of individual items, though in most cases only one of the it ems generated lay outside the range of equivalence, and could be eliminated. Examinations with a large number of graphic items take somewhat longer. The multiple choice items that make up these examinations have an appropriate range of distractors and are graphically clear and attractive. At present, the test must be delivered already printed up. However, project staff hopes to make possible computer delivery of the examinations to individual student test takers, with immediate feedback on test results.
Staff are also at work on incorp orating calculator-based items into tests.
The items were field-tested on a student samples ranging from 264 to 584 for each type of test to determine test and item equivalence. For four of the five tests, the four different versions were equivalent within a range of three to four percent on a 100 point scale. Work will continue to reduce the seven percent variance on the fifth test. The spread on individual items was much greater, sometimes as large as 40 percent. These variances were greater for the smaller sample sizes, suggesting that a larger sample size might reduce the range of variance.