Based on empirical studies, EDI-3 has reasonable face validity for the population the instrument was designed for (11 to 53-year-old female population). However, Atlas (2007) and Kagee (2007) recommend further testing of construct validity and EDI-3 application to cross-cultural populations. Atlas found the empirical evidence was limited and disappointing, suggesting the screening components were more helpful than the scales.
Technical evaluation Norms EDI-3 relies on the age and diagnostic status of individuals. Age effects can influence some sub-scales when comparing adolescents and adults. Therefore, two normative groups were derived: 11 to 17 years, and 18 years and older. There was no normative group for those under 11 or…show more content… EDI-3 does not include norms for males. Smith et al. (2017) developed a set of male norms for EDI-3 and Eating Disorder Examination Questionaire (EDE-Q). They compared males (n = 386) with females (n = 1487) who had been clinically diagnosed eating disorders. The research observed greater eating disorder severity in females which made it unclear if differences between genders were responsible or something else. Additional studies of male-specific clinical samples are necessary to clarify if the scales are relevant and appropriate when developing male norms. Reliability There is one 91-item form used to test individuals in a clinical or research setting. Those with no-psychology training use a shortened version of the form. The assessment form is from a previous versions of the assessment (EDI, EDI-2) and reliability between earlier versions of the test and EDI-3 is possible and equivalent for the same items. Overall the reliability was sound; however, low-reliability coefficients on the Bulimia scale for Anorexia Nervosa Restricted (AN-R) diagnostic (.63) were found (Garner, 2004). Norm group reliability was assessed across groups (N = 1980) female patients (US adult (n = 983), international clinical population (n = 662), and a US adolescent clinical population (n = 335)) who already met the diagnostic criteria for an eating disorder (Atlas, 2007). Across the three normative groups, and diagnostic categories (ANR, ANB, BN, EDNOS) a composite T-score