The Performance Diagnostic Checklist-Human Services (PDC-HS) has been used to assess variables contributing to undesirable staff performance. In this study, three preschool teachers completed the PDC-HS to identify the factors contributing to four paraprofessionals' inaccurate implementation of error-correction procedures during discrete trial training sessions. The PDC-HS indicated insufficient training as a contributing factor. We then implemented a nonindicated intervention (posting reminders), followed by an indicated intervention (behavioral skills training). The nonindicated intervention failed to produce desired performance improvements; however, the PDC-HS indicated intervention resulted in improvements for all paraprofessionals.