An Experimental Study of the Effects on Item-Analysis Data of Changing Item Placement and Test Time Limit
- 1 September 1950
- journal article
- Published by Cambridge University Press (CUP) in Psychometrika
- Vol. 15 (3) , 291-315
- https://doi.org/10.1007/bf02289044
Abstract
Item-analysis data are usually obtained from a single test administration, with a given item sequence and time limit. Questions can be raised as to the effects upon item data resulting from changes in item-position and test-timing. In this study, two forms of a verbal test and two forms of a mathematics test were used. In each case, both forms of each test contained the same items, but items coming early in one form were placed late in the other. Each of these forms was administered once with a short time limit and once with generous timing to comparable groups of high school students. The relationships of various speed and power scores were determined, and the changes which occurred during the added time were studied. Values of the item indices p (proportion right), Δ† (another difficulty index), and the item-test biserial correlation coefficient were obtained for both the speed and the power conditions and were systematically compared. The proportion right of those attempting the item, the Δ index, and the biserial r were all found to have undesirable characteristics for items appearing late in a speeded test.Keywords
This publication has 3 references indexed in Scilit:
- Effect of Speed On Item-Test Correlation CoefficientsEducational and Psychological Measurement, 1949
- Characteristics and uses of item-analysis data.Psychological Monographs: General and Applied, 1948
- Item validity as a factor in test validity.Journal of Educational Psychology, 1940