Miller G.A. Misunderstanding Analysis of Covariance

/Миллер Дж. Непонимание ковариационного анализа/ Joual of Abnormal Psychology, vol. 110, no. 1, pp. 40-48. Despite numerous technical treatments in many venues, analysis of covariance (ANCOVA) remains a widely misused approach to dealing with substantive group differences on potential covariates, particularly in psychopathology research. Published articles reach unfounded conclusions, and some statistics texts neglect the issue. The problem with ANCOVA in such cases is reviewed. In many cases, there is no means of achieving the superficially appealing goal of "correcting" or "controlling for" real group differences on a potential covariate. In hopes of curtailing misuse of ANCOVA and promoting appropriate use, a nontechnical discussion is provided, emphasizing a substantive confound rarely articulated in textbooks and other general presentations, to complement the mathematical critiques already available. Some alteatives are discussed for contexts in which ANCOVA is inappropriate or questionable. /В статье рассмотрена ошибка психологических исследований, использующих в качестве ковариаты информацию о различии выборок с целью контроля нерандомизированных групп, набранных из разных генеральных совокупностей/