Our paper empirically tests the distinction between procedural justice (or the fairness of organizational procedures) and interactional justice (or the fairness of the interpersonal treatment received during the enactment of procedures). The distinctiveness of these two types of justice had been a topic of continuing debate within the organizational justice literature. Our results demonstrate that the two types of justice work through different mediating variables to influence different sets of outcomes, and thus should be treated as distinct in future research. Moreover, the paper provides a test of social exchange variables as a mechanism for the impact of justice perceptions on subsequent reactions—a mechanism that had been theoretically described but not fully empirically tested. Our results demonstrate that justice perceptions appear to work through impacting employees' perceptions of their social exchange relationship; that is, fair acts are seen as a contribution to the relationship with the employee, and thus the employee feels obligated to reciprocate through positive attitudes and behaviors.

We utilized structural equation modeling (using EQS) in order to simultaneously test the two types of justice, two mediating variables, and six outcomes variables. Previous research had looked at various subsets of the variables, but never the full set. By studying all of the variables simultaneously and thus pitting them against one another, we were able to fully depict the complex pattern of relationships among these interconnected variables.

We had been following with interest the debate over the distinctiveness of procedural versus interactional justice, when we were offered an opportunity to create a new performance appraisal system for a large organization. This offered an organizational setting in which we could empirically test the two types of justice, along with the social exchange relationships and subsequent outcomes.

Our results offer practical implications for organizations, through demonstrating that employees react to several different types of fairness, including the fairness of organizational procedures (in this study, performance appraisal procedures) and the fairness of their supervisor's interpersonal treatment. Each type of fairness impacts different social exchange relationships and subsequent reactions, so organizations are well advised to measure and make improvements in each.