TY - JOUR
T1 - Interacting With Curves
T2 - How to Validly Test and Probe Interactions in the Real (Nonlinear) World
AU - Simonsohn, U.
N1 - Publisher Copyright:
© The Author(s) 2024.
PY - 2024/1/1
Y1 - 2024/1/1
N2 - Hypotheses involving interactions in which one variable modifies the association between another two are very common. They are typically tested relying on models that assume effects are linear, for example, with a regression like y = a + bx + cz + dx × z. In the real world, however, few effects are linear, invalidating inferences about interactions. For instance, in realistic situations, the false-positive rate can be 100% for detecting an interaction, and a probed interaction can reliably produce estimated effects of the wrong sign. In this article, I propose a revised toolbox for studying interactions in a curvilinear-robust manner, giving correct answers “even” when effects are not linear. It is applicable to most study designs and produces results that are analogous to those of current—often invalid—practices. The presentation combines statistical intuition, demonstrations with published results, and simulations.
AB - Hypotheses involving interactions in which one variable modifies the association between another two are very common. They are typically tested relying on models that assume effects are linear, for example, with a regression like y = a + bx + cz + dx × z. In the real world, however, few effects are linear, invalidating inferences about interactions. For instance, in realistic situations, the false-positive rate can be 100% for detecting an interaction, and a probed interaction can reliably produce estimated effects of the wrong sign. In this article, I propose a revised toolbox for studying interactions in a curvilinear-robust manner, giving correct answers “even” when effects are not linear. It is applicable to most study designs and produces results that are analogous to those of current—often invalid—practices. The presentation combines statistical intuition, demonstrations with published results, and simulations.
KW - Social behavior
KW - Social cognition
UR - http://www.scopus.com/inward/record.url?scp=85186864811&partnerID=8YFLogxK
U2 - 10.1177/25152459231207787
DO - 10.1177/25152459231207787
M3 - Article
AN - SCOPUS:85186864811
SN - 2515-2459
VL - 7
JO - Advances in Methods and Practices in Psychological Science
JF - Advances in Methods and Practices in Psychological Science
IS - 1
M1 - 25152459231207787
ER -