Open AccessAN ALTERNATE DEFINITION OF THE ETS DELTA SCALE OF ITEM DIFFICULTY
Author(s) -
Holland Paul W.,
Thayer Dorothy T.
Publication year - 1985
Publication title -
ets research report series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.235
H-Index - 5
ISSN - 2330-8516
DOI - 10.1002/j.2330-8516.1985.tb00128.x
Subject(s) - scale (ratio) , delta , econometrics , statistics , distribution (mathematics) , psychology , mathematics , computer science , geography , cartography , mathematical analysis , aerospace engineering , engineering
This note develops an alternative definition of the “delta scale” of item difficulty that is used at ETS. A comparison is given with the traditional definition of the delta scale that is based on the normal distribution. Some advantages of the alternative scale are mentioned.