Test Score Equating Using Discrete Anchor Items Versus Passage-Based Anchor Items: A Case Study Using SAT Data
- Author(s):
- Liu, Jinghua; Zu, Jiyun; Curley, W. Edward; Carey, Jill
- Publication Year:
- 2014
- Report Number:
- RR-14-14
- Source:
- ETS Research Report
- Document Type:
- Report
- Page Count:
- 12
- Subject/Key Words:
- Anchor Test Equating, Discrete Anchor Items, Passage-Based Anchor Items, Local Item Dependence, SAT
Abstract
The purpose of this study is to investigate the impact of discrete anchor items versus passage-based anchor items on observed score equating using empirical data. This study compares an SAT critical reading anchor that contains more discrete items proportionally, compared to the total tests to be equated, to another anchor that contains fewer discrete items and more passage-based items proportionally. Both of these anchors were administered in an SAT administration. The impact of anchor type on equating was evaluated with respect to equating bias. The results clearly reveal that the anchor with more discrete items almost always leads to more accurate equating functions than does the anchor with more passage-based items.
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- http://dx.doi.org/10.1002/ets2.12015