TY  - JOUR
A1  - Miller, Jeff
A1  - Schwarz, Wolfgang
T1  - Implications of Individual Differences in On-Average Null Effects
JF  - Journal of experimental psychology : General
N2  - Most psychological models are intended to describe processes that operate within each individual. In many research areas, however, models are tested by looking at results averaged across many individuals, despite the fact that such averaged results may give a misleading picture of what is true for each one. We consider this conundrum with respect to the interpretation of on-average null effects. Specifically, even though an experimental manipulation might have no effect on average across individuals, it might still have demonstrable effects-albeit in opposite directions-for many or all of the individuals tested. We discuss several examples of research questions for which it would be theoretically crucial to determine whether manipulations really have no effect at the individual level, and we present a method of testing for individual-level effects.
KW  - null effects
KW  - individual differences
KW  - hypothesis testing
KW  - psychological models
Y1  - 2018
U6  - https://doi.org/10.1037/xge0000367
SN  - 0096-3445
SN  - 1939-2222
VL  - 147
IS  - 3
SP  - 377
EP  - 397
PB  - American Psychological Association
CY  - Washington
ER  -