NotesFAQContact Us
Search Tips
ERIC Number: EJ835198
Record Type: Journal
Publication Date: 2008
Pages: 14
Abstractor: As Provided
Reference Count: 21
ISSN: ISSN-1598-1037
A New Approach to Test Score Equating Using Item Response Theory with Fixed C-Parameters
Lee, Guemin; Fitzpatrick, Anne R.
Asia Pacific Education Review, v9 n3 p248-261 2008
Because parameter estimates from different calibration runs under the IRT model are linearly related, a linear equation can convert IRT parameter estimates onto another scale metric without changing the probability of a correct response (Kolen & Brennan, 1995, 2004). This study was designed to explore a new approach to finding a linear equation by fixing C-parameters for anchor items in IRT equating. A rationale for fixing C-parameters for anchor items in IRT equating can be established from the fact that the C-parameters are not affected by any linear transformation. This new approach can avoid the difficulty in getting accurate C-parameters for anchor items embedded in the application of the IRT model. Based upon our findings in this study, we would recommend using the new approach to fix C-parameters for anchor items in IRT equating. (Contains 6 tables and 3 figures.)
Education Research Institute, Seoul National University. Department of Education, 599 Kwanak-Ro, Kwanak-Gu, Seoul 151-748, South Korea. Tel: +82-2-880-5896; Fax: +82-2-889-6508; e-mail:; Web site:
Publication Type: Journal Articles; Reports - Evaluative
Education Level: Grade 11; Grade 4; Grade 7
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A
Identifiers - Assessments and Surveys: TerraNova Multiple Assessments