|
University of Minnesota Digital Conservancy >
University of Minnesota - Twin Cities >
Applied Psychological Measurement >
Volume 17, 1993 >
Please use this permanent URL to cite or link to this item:
http://purl.umn.edu/116376
|
| Title: | Scale shrinkage in vertical equating |
| Authors: | Camilli, Gregory
Yamamoto, Kentaro
Wang, Ming-mei |
| Issue Date: | 1993 |
| Citation: | Camilli, Gregory, Yamamoto, Kentaro & Wang, Ming-mei. (1993). Scale shrinkage in vertical equating. Applied Psychological Measurement, 17, 379-388. doi:10.1177/014662169301700407 |
| Abstract: | As an alternative to equipercentile equating in the
area of multilevel achievement test batteries, item
response theory (IRT) vertical equating has
produced unexpected results. When expanded standard
scores were obtained to link the Comprehensive
Test of Basic Skills and the California Achievement
Test, the variance of test scores diminished both
within particular grade levels from fall to spring,
and also from lower to upper grade levels. Equipercentile
equating, on the other hand, has resulted
in increasing variance both within and across grade
levels, although the increases are not linear across
grade levels. Three potential causes of scale shrinkage
are discussed, and a more comprehensive,
model-based approach to establishing vertical
scales is described. Test data from the National
Assessment of Educational Progress were used to
estimate the distribution of ability at grades 4, 8,
and 12 for several math achievement subtests. For
each subtest, the variance of scores increased from
grade 4 to grade 8; however, beyond grade 8 the
results were not uniform. Index terms: developmental
scores, equating, IRT scaling, maximum likelihood
estimation, National Assessment of Educational
Progress (NAEP), scale shrinkage, vertical equating. |
| Permanent URL: | http://purl.umn.edu/116376 |
| Appears in Collections: | Volume 17, 1993
|
Files in This Item:
| File |
Description |
Size | Format |
|---|
| v17n4p379.pdf | | 1066Kb | PDF | View/Open |
|
Items in the Digital Conservancy are protected by copyright, with all rights reserved, unless otherwise indicated.
|
