Open AccessREDUCING TYPE‐2 SAMPLING ERRORS IN THE ESTIMATION OF TEST RELIABILITY
Author(s) -
Lord Frederic M.
Publication year - 1955
Publication title -
ets research bulletin series
Language(s) - English
Resource type - Journals
eISSN - 2333-8504
pISSN - 0424-6144
DOI - 10.1002/j.2333-8504.1955.tb00258.x
Subject(s) - statistics , reliability (semiconductor) , variance (accounting) , sampling (signal processing) , test (biology) , mathematics , computer science , quantum mechanics , business , computer vision , biology , paleontology , power (physics) , physics , accounting , filter (signal processing)
ABSTRACT The formula and derivation are given for the sampling variance of the “random‐halves” reliability coefficient when items, rather than examinees, are sampled. When the number of test items is large, this sampling variance is found to be larger than the Kuder‐Richardson formula‐20 coefficient by a factor equal to the number of test items. The usual matched‐halves reliability coefficient will likewise usually have a large sampling variance, since it likewise is based on an arbitrary split of the test items. An adaptation of the Jackson‐Ferguson “battery reliability coefficient,” used as an estimate of the matched‐forms reliability of the test, avoids this relatively large sampling variance.