title: The subjects as a simple random effect fallacy: subject variability and morphological family effects in the mental lexicon.
abstract: This is a methodological study addressing the appropriateness of standard by-subject and by-item averaging procedures for the analysis of repeated-measures designs. By means of a reanalysis of published data (Schreuder & Baayen, 1997), using random regression models, we present a proof of existence of systematic variability between participants that is ignored in the standard psycholinguistic analytical procedures. By applying linear mixed effects modeling (Pinheiro & Bates, 2000), we call attention to the potential lack of power of the by-subject and by-item analyses, which in this case study fail to reveal the coexistence of a facilitatory family size effect and an inhibitory family frequency effect in visual and auditory lexical processing.
authors.affiliation: Interfaculty Research Unit for Language and Speech, Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands. baayen@mpi.nl
authors.forename: R Harald
authors.initials: RH
authors.lastname: Baayen
authors.forename: Fiona J
authors.initials: FJ
authors.lastname: Tweedie
authors.forename: Robert
authors.initials: R
authors.lastname: Schreuder
mesh_terms: D001307:Auditory Perception; D003071:Cognition; D006801:Humans; D008960:Models, Psychological; D011578:Psycholinguistics / Q000379:methods; D014796:Visual Perception; D014825:Vocabulary