We found a matchYour institution may have access to this item. Find your institution then sign in to continue.TitleEffects of study duration, frequency of observation, and sample size on power in studies of group differences in polynomial change.AuthorsRaudenbush, Stephen W.; Liu, Xiao-FengPublicationPsychological Methods, 2001, Vol 6, Issue 4, p387ISSN1082-989xPublication typearticleDOI10.1037/1082-989X.6.4.387