naa a22 4500 510776620 CHVBK 20180411083232.0 cr unu---uuuuu 180411e20130301xx s 000 0 eng 10.3758/s13428-012-0225-x doi (NATIONALLICENCE)springer-10.3758/s13428-012-0225-x Assessing bimodality to detect the presence of a dual cognitive process [Elektronische Daten] [Jonathan Freeman, Rick Dale] Researchers have long sought to distinguish between single-process and dual-process cognitive phenomena, using responses such as reaction times and, more recently, hand movements. Analysis of a response distribution's modality has been crucial in detecting the presence of dual processes, because they tend to introduce bimodal features. Rarely, however, have bimodality measures been systematically evaluated. We carried out tests of readily available bimodality measures that any researcher may easily employ: the bimodality coefficient (BC), Hartigan's dip statistic (HDS), and the difference in Akaike's information criterion between one-component and two-component distribution models (AICdiff). We simulated distributions containing two response populations and examined the influences of (1) the distances between populations, (2) proportions of responses, (3) the amount of positive skew present, and (4) sample size. Distance always had a stronger effect than did proportion, and the effects of proportion greatly differed across the measures. Skew biased the measures by increasing bimodality detection, in some cases leading to anomalous interactive effects. BC and HDS were generally convergent, but a number of important discrepancies were found. AICdiff was extremely sensitive to bimodality and identified nearly all distributions as bimodal. However, all measures served to detect the presence of bimodality in comparison to unimodal simulations. We provide a validation with experimental data, discuss methodological and theoretical implications, and make recommendations regarding the choice of analysis. Psychonomic Society, Inc., 2012 Bimodality nationallicence Response distribution nationallicence Dual-process models nationallicence Single-process models nationallicence Mouse-tracking nationallicence Freeman Jonathan Department of Psychological & Brain Sciences, Dartmouth College, 6207 Moore Hall, 03755, Hanover, NH, USA aut Dale Rick University of California, Merced, Merced, CA, USA aut Behavior Research Methods Springer-Verlag 45/1(2013-03-01), 83-97 45:1<83 2013 45 13428 https://doi.org/10.3758/s13428-012-0225-x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.3758/s13428-012-0225-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Freeman Jonathan Department of Psychological & Brain Sciences, Dartmouth College, 6207 Moore Hall, 03755, Hanover, NH, USA aut NATIONALLICENCE 700 1- Dale Rick University of California, Merced, Merced, CA, USA aut NATIONALLICENCE 773 0- Behavior Research Methods Springer-Verlag 45/1(2013-03-01), 83-97 45:1<83 2013 45 13428 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer