The U.S. Department of Labor's Assessment Research and Development Program proposed the Validation Methods Research Project to correct many of the problems noted by the National Academy of Sciences (NAS) with the use of the General Aptitude Test Battery (GATB) as a tool for screening and referring applicants to prospective employers. One of the project's goals was the development of a biodata form as a supplement to the GATB due to evidence for biodata's validity, in particular its incremental validity over that obtained with cognitive ability tests, and its low adverse impact. Results of the study to develop and validate a biodata measure (Salesperson Biodata Questionnaire; SBQ) to select salespersons are provided. A construct-rational approach was used in construction of the SBQ, and a concurrent validation study was conducted to evaluate the validity of a revised form of the GATB and the SBQ. The SBQ showed significant incremental validities over the GATB for predicting four performance composites and Overall Performance. Leadership, Self-Motivation, Dependability, and Multi-tasking Ability were the strongest predictors of salesperson job performance. The value of the multivariate framework and several patterns of relationships that emerged in the study are discussed.