Využitie a zneužitie Cronbachovej alfy pri hodnotení psychodiagnostických nástrojov
č.7(2016)
Na základe výsledkov testovania prebiehajúcom v psychologickej diagnostike, vznikajú závery a rozhodnutia, ktorých validita kriticky závisí od spoľahlivosti využitých posudzovacích metód. Reliabilita nástroja je z tohto dôvodu kľúčovým pojmom pri posudzovaní akéhokoľvek psychologického atribútu. Napriek množstvu alternatív, najvýznamnejším a najpoužívanejším indikátorom kvality testového skóre ostáva sprofanovaný koeficient vnútornej konzistencie - alfa (Cronbach, 1951). Postupne identifikujeme najzávažnejšie omyly a problémy, ktoré sa pri používaní tejto štatistiky opakovane objavujú. K jednotlivým bodom taktiež ponúkame riešenia, ktoré by mohli prispieť k zlepšeniu odhadu kvality skóre testovacích nástrojov a rozhodnutí, ktoré sa o ne opierajú.
The validity of inferences and decisions formed on the basis of testing in psychological diagnostics is critically dependent on reliability of utilized assessment tools. Therefore, whenever a psychological attribute is to be scored, reliability of the diagnostic means becomes crucial. Despite many alternatives, Cronbach’s alpha (1951), as profaned internal consistency statistic, remains the most prominent and most widely used indicator of test score quality. Because of this importance, our article is aimed to identify the most serious misconceptions and misapplications which repeatedly occur when using this statistics. For each particular point of this issue, we suggest a simple solution which may improve the estimation of the score quality of tests and therefore enhance decisions that are drawn from them.
reliabilita; Cronbachova alfa; vnútorná konzistencia; psychomerika; reliability; Cronbach's Alpha; internal consistency; psychometrics
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