ERIC Number: ED189100
Record Type: RIE
Publication Date: 1978
Reference Count: 0
Linking Groups of Items. Portland Public Schools Occasional Papers in Measurement No. 19.
Forster, Fred; Ingebo, George
In Rasch terminology, two or more tests are linked when they are joined into a pool related to a single scale. When the same item calibrates at a low level on one test and a high level on a second test, it indicates that the item is low on the first test because the other items on that test are higher, and is high on the second test because the other items on that test are lower. The difference between the average of the calibrations of a subset of items on one test and the average for the same items on a second test is called the linking value. The accuracy of a linking value can be established by confirmation through the use of a third test, an algebraic process known as triangulation. The pattern of links between pairs of field tests is called a linking network. The purpose for the network is to insure that sufficient information will be available to calculate accurate linking values for each test to the final scale. Four types of linking networks can be used: the four square network, the three-by-three network, the double eight linking network , and the octagon linking network. (Author/BW)
Publication Type: Guides - Non-Classroom
Education Level: N/A
Authoring Institution: Northwest Evaluation Association, OR.; Portland Public Schools, OR.
Identifiers: Item Calibration; Rasch Model; Test Linking