This study describes the development of a multidimensional biodata form which used explicit constructs to guide item generation and rational scale development, construct validation, criterion measurement and empirical keying. These constructs were goal-orientation, teamwork, customer service, resourcefulness, learning ability and leadership. Exploratory and confirmatory factor analyses in both applicant and incumbent samples were used to identify and test the model which included the thirteen, more differentiated rational scales relating to these six, broader constructs. Empirical keying of the rationally developed scales was conducted against criterion construct scales conceptually related to each predictor construct. Empirical keying at the item level was found to result in higher validities and crossvalidities than either empirical keying at the scale level, or rational keying. The item keyed instrument also demonstrated incremental validity over a test of cognitive ability for specific work performance domains as well as overall work performance.T he term biodata represents a selection methodology of scoring biographical or past behaviour information in a manner that maximizes prediction of an external criterion. Within industrial-organizational psychology, biodata has been shown to predict a range of criteria including work performance (Hunter and Hunter 1984), training outcomes (Drakely, Herriot and Jones 1988) and turnover (Reilly and Chao 1982). An increasingly common practice amongst biodata researchers (Hough and Paullin 1994;Mael 1991;Stokes, Hogan, and Snell 1993) has been the specification of constructs and distal psychological processes measured by biodata forms. In order to further increase psychological substantiveness, biodata item generation can be guided by general theoretical frameworks such as the social ecology model (Mael 1991), or by specific hypotheses regarding the relationship between a given biodata item and the criterion (Mumford and Owens 1987). Such trends are likely not only to improve the interpretability of a given biodata form, but also enhance theory development on the relationship between past, nonwork behaviour and work-related criteria.Issues related to psychological substantiveness of biodata have also emerged in the debate regarding the relative merits of the two major methods of scoring biodata items; rational and empirical keying. In rational keying, item scoring is based on a priori, theoretical judgements that guide item development. Typically, stronger endorsements of items are taken to reflect higher levels of a given construct, and are therefore assigned higher scores on that construct. Rational item generation and scoring tend to occur in conjunction even though they are distinguishable stages in the development of biodata forms. The rational item generation and scoring approach has been associated with scientific advancement in that it progresses understanding of factors and processes linking predictors and work performance (Hough and Paullin 1994).Empirical keyin...