ERIC Number: ED507815
Record Type: Non-Journal
Publication Date: 2009-Dec
Pages: 53
Abstractor: As Provided
ISBN: N/A
ISSN: N/A
EISSN: N/A
Available Date: N/A
The Effects of Different Types of Anchor Tests on Observed Score Equating. Research Report. ETS RR-09-41
Liu, Jinghua; Sinharay, Sandip; Holland, Paul W.; Feigenbaum, Miriam; Curley, Edward
Educational Testing Service
This study explores the use of a different type of anchor, a "midi anchor", that has a smaller spread of item difficulties than the tests to be equated, and then contrasts its use with the use of a "mini anchor". The impact of different anchors on observed score equating were evaluated and compared with respect to systematic error (bias), random equating error (standard errors of equating), and total equating error (RMSE) using empirical data. The results show that the midi anchor generally produces more accurate equating results than the mini anchor--with a few exceptions. Our findings suggest that a midi anchor test would be preferred to a mini anchor test if equating accuracy at the top and at the bottom of the score scale is not a primary concern. (Contains 11 tables, 24 figures, and 1 note.)
Descriptors: Equated Scores, Test Items, Difficulty Level, Error of Measurement, Bias, Raw Scores, Statistical Analysis, College Entrance Examinations
Educational Testing Service. Rosedale Road Mailstop 19R, Princeton, NJ 08541-0001. Tel: 609-921-9000; Fax: 609-734-5410; Web site: http://www.ets.org
Publication Type: Reports - Research
Education Level: N/A
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: Educational Testing Service
Identifiers - Assessments and Surveys: SAT (College Admission Test)
Grant or Contract Numbers: N/A
Author Affiliations: N/A