Open AccessAn index of validity that corrects for chance agreement
Author(s) -
Newman Stephen C.
Publication year - 1998
Publication title -
international journal of methods in psychiatric research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.275
H-Index - 73
eISSN - 1557-0657
pISSN - 1049-8931
DOI - 10.1002/mpr.49
Subject(s) - kappa , index (typography) , cohen's kappa , youden's j statistic , reliability (semiconductor) , statistics , mathematics , agreement , psychology , computer science , thermodynamics , receiver operating characteristic , geometry , physics , power (physics) , world wide web , linguistics , philosophy
Cohen's (1960) kappa coefficient, κ, is a well‐known index of reliability that corrects for chance agreement. The maximum and minimum values of kappa are examined. Using kappa as a theoretical framework, an index of validity is derived for the case of binary outcomes that summarizes sensitivity and specificity. This index is shown to be identical to the coefficient derived by Youden (1950). Copyright © 1998 Whurr Publishers Ltd.