2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/142841We derive an asymptotic power function for a likelihood-based test for interaction in a regression model, with possibly misspecified alternative distribution. This allows a general investigation of types of interactions which are poorly or well detected via data. Principally we contrast pairwise-interaction models with `diffuse interaction models' as introduced in Gustafson, Kazi, and Levy (2005).Submitted to the Electronic Journal of Statistics (http://www.i-journals.org/ejs/) by the Institute of Mathematical Statistics (http://www.imstat.org)Statistics Theorytext