Detecting differential item functioning in behavioral indicators across parallel forms

Background: Despite the crucial importance of the notion of parallel forms within Classical Test Theory, the degree of parallelism between two forms of a test cannot be directly verified due to the unobservable nature of true scores. We intend to overcome some of the limitations of traditional appro...

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Detalhes bibliográficos
Autores: Gómez Benito, Juana, González, Andrés, Widaman, Keith F., Padilla, José Luis, Balluerka Lasa, Nekane
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2017
País:España
Recursos:Universidad de Barcelona
Repositório:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/121117
Acesso em linha:https://hdl.handle.net/2445/121117
Access Level:Acceso aberto
Palavra-chave:Tests psicològics
Psicometria
Psychological tests
Psychometrics
Descrição
Resumo:Background: Despite the crucial importance of the notion of parallel forms within Classical Test Theory, the degree of parallelism between two forms of a test cannot be directly verified due to the unobservable nature of true scores. We intend to overcome some of the limitations of traditional approaches to analyzing parallelism by using the Differential Item Functioning framework. Method: We change the focus on comparison from total test scores to each of the items developed during test construction. We analyze the performance of a single group of individuals on parallel items designed to measure the same behavioral criterion by several DIF techniques. The proposed approach is illustrated with a dataset of 527 participants that responded to the two parallel forms of the Attention Deficit-Hyperactivity Disorder Scale (Caterino, Gómez-Benito, Balluerka, Amador-Campos, & Stock, 2009). Results: 12 of the 18 items (66.6%) show probability values associated with the Mantel χ2 statistic of less than .01. The standardization procedure shows that half of DIF items favoured Form A and the other half Form B. Conclusions: The "differential functioning of behavioral indicators" (DFBI) can provide unique information on parallelism between pairs of items to complement traditional analysis of equivalence between parallel test forms based on total scores.