Open AccessMODELING ITEM RESPONSES WHEN DIFFERENT SUBJECTS EMPLOY DIFFERENT SOLUTION STRATEGIES 1
Author(s) -
Mislevy Robert J.,
Verhelst Norman
Publication year - 1987
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.2330-8516.1987.tb00251.x
Subject(s) - set (abstract data type) , item response theory , population , psychology , statistics , mathematics , econometrics , cognitive psychology , computer science , psychometrics , demography , sociology , programming language
A model is presented for item responses when different examinees employ different strategies to arrive at their answers, and when only those answers, not choice of strategy or subtask results, can be observed. Using substantive theory to differentiate the likelihoods of response vectors under a fixed set of solution strategies, we model responses in terms of item parameters associated with each strategy, proportions of the population employing each, and the distributions of examinee parameters within each. Posterior distributions can then be obtained for each examinee, giving the probabilities that they employed each of the strategies and their proficiency under each. The ideas are illustrated with a conceptual example about response strategies for spatial rotation items, and a numerical example resolving a population of examinees into subpopulations of valid responders and random guessers.