{"database":"biostudies-literature","file_versions":[],"scores":null,"additional":{"omics_type":["Unknown"],"volume":["82(6)"],"submitter":["Miyazaki Y"],"pubmed_abstract":["This paper investigated consequences of measurement error in the pretest on the estimate of the treatment effect in a pretest-posttest design with the analysis of covariance (ANCOVA) model, focusing on both the direction and magnitude of its bias. Some prior studies have examined the magnitude of the bias due to measurement error and suggested ways to correct it. However, none of them clarified how the direction of bias is affected by measurement error. This study analytically derived a formula for the asymptotic bias for the treatment effect. The derived formula is a function of the reliability of the pretest, the standardized population group mean difference for the pretest, and the correlation between pretest and posttest true scores. It revealed a concerning consequence of ignoring mea"],"journal":["Educational and psychological measurement"],"pagination":["1130-1152"],"full_dataset_link":["https://www.ebi.ac.uk/biostudies/studies/S-EPMC9619320"],"repository":["biostudies-literature"],"pubmed_title":["Bias for Treatment Effect by Measurement Error in Pretest in ANCOVA Analysis."],"pmcid":["PMC9619320"],"pubmed_authors":["Uekawa K","Miyazaki Y","Kamata A","Sun Y"],"additional_accession":[]},"is_claimable":false,"name":"Bias for Treatment Effect by Measurement Error in Pretest in ANCOVA Analysis.","description":"This paper investigated consequences of measurement error in the pretest on the estimate of the treatment effect in a pretest-posttest design with the analysis of covariance (ANCOVA) model, focusing on both the direction and magnitude of its bias. Some prior studies have examined the magnitude of the bias due to measurement error and suggested ways to correct it. However, none of them clarified how the direction of bias is affected by measurement error. This study analytically derived a formula for the asymptotic bias for the treatment effect. The derived formula is a function of the reliability of the pretest, the standardized population group mean difference for the pretest, and the correlation between pretest and posttest true scores. It revealed a concerning consequence of ignoring mea","dates":{"release":"2022-01-01T00:00:00Z","publication":"2022 Dec","modification":"2025-04-22T13:44:31.872Z","creation":"2025-04-06T00:49:27.466Z"},"accession":"S-EPMC9619320","cross_references":{"pubmed":["36325124"],"doi":["10.1177/00131644211068801"]}}