Skip to main content

Research Repository

Advanced Search

Unmasking the unasked: correcting the record about assessor masking as an explanation for effect size differences

Simpson, A.

Unmasking the unasked: correcting the record about assessor masking as an explanation for effect size differences Thumbnail


Authors



Abstract

Ainsworth et al.’s paper “Sources of Bias in Outcome Assessment in Randomised Controlled Trials: A Case Study” examines alternative accounts for a large difference in effect size between 2 outcomes in the same intervention evaluation. It argues that the probable explanation relates to masking: Only one outcome measure was administered by those aware of participants’ treatment assignment. This paper shows this conclusion is not substantiated by the evidence: The original paper fails to exclude alternative explanations, and what it takes as positive evidence for the preferred explanation is actually negative. While accepting the importance of masking in randomised controlled trials, this paper concludes that the original question was based on a misconception about effect sizes: Seen correctly as a measure of whole study design, the question of effect size difference between different outcome measures does not need asking.

Citation

Simpson, A. (2018). Unmasking the unasked: correcting the record about assessor masking as an explanation for effect size differences. Educational Research and Evaluation, 24(1-2), 3-12. https://doi.org/10.1080/13803611.2018.1520131

Journal Article Type Article
Acceptance Date Aug 31, 2018
Online Publication Date Oct 12, 2018
Publication Date Oct 12, 2018
Deposit Date Aug 20, 2018
Publicly Available Date Apr 12, 2020
Journal Educational Research and Evaluation
Print ISSN 1380-3611
Electronic ISSN 1744-4187
Publisher Taylor and Francis Group
Peer Reviewed Peer Reviewed
Volume 24
Issue 1-2
Pages 3-12
DOI https://doi.org/10.1080/13803611.2018.1520131

Files





You might also like



Downloadable Citations