Levin, Joel R.Subkoviak, Michael J.2011-01-072011-01-071977Levin, Joel R. & Subkoviak, Michael J. (1977). Planning an experiment in the company of measurement error. Applied Psychological Measurement, 1, 331-338. doi:10.1177/014662167700100302doi:10.1177/014662167700100302https://hdl.handle.net/11299/98556"Textbook" calculations of statistical power and/or sample size follow from formulas that assume that the variables under consideration are measured without error. However, in the "real world" of behavioral research, errors of measurement cannot be neglected. A recent sample-size determination approach is easily adapted to incorporate unreliability information for both completely randomized and randomized block analysis-of-variance designs. A worked example presents an instance wherein a blocking strategy is clearly advantageous assuming infallible measuring instruments, but not when the same instruments are granted fallibility.enArticle