TY  - JOUR
A1  - Schwarz, Wolfgang
A1  - Reike, Dennis
T1  - Regression away from the mean
BT  - theory and examples
JF  - British journal of mathematical and statistical psychology / British Psychological Society
N2  - Using a standard repeated measures model with arbitrary true score distribution and normal error variables, we present some fundamental closed-form results which explicitly indicate the conditions under which regression effects towards (RTM) and away from the mean are expected. Specifically, we show that for skewed and bimodal distributions many or even most cases will show a regression effect that is in expectation away from the mean, or that is not just towards but actually beyond the mean. We illustrate our results in quantitative detail with typical examples from experimental and biometric applications, which exhibit a clear regression away from the mean (‘egression from the mean’) signature. We aim not to repeal cautionary advice against potential RTM effects, but to present a balanced view of regression effects, based on a clear identification of the conditions governing the form that regression effects take in repeated measures designs.
KW  - bimodality
KW  - measurement error
KW  - non-normality
KW  - regression towards the mean
KW  - repeated measures
KW  - skewed distributions
Y1  - 2017
U6  - https://doi.org/10.1111/bmsp.12106
SN  - 0007-1102
SN  - 2044-8317
VL  - 71
IS  - 1
SP  - 186
EP  - 203
PB  - Wiley
CY  - Hoboken
ER  -