<P> The idea of the participation model is that a fair procedure is one that affords those who are affected by an opportunity to participate in the making of the decision . In the context of a trial, for example, the participation model would require that the defendant be afforded an opportunity to be present at the trial, to put on evidence, cross examination witnesses, and so forth . </P> <P> Models have also been proposed to understand the psychological basis of justice . One of the more recent of these models is the group engagement model . The group engagement model (GEM), devised by Tom R. Tyler and Steven L. Blader, incorporates past psychological theories to explain the underlying psychological processes of procedural justice . Based on social identity theory and relational models of procedural justice, this model suggests that a group's procedural justice process influences members' identification with the group, which in turn influences their type of engagement within the group . </P> <P> According to the model, group engagement is seen as either mandatory or discretionary behavior . Mandatory behavior is defined by Tyler and Blader as behavior that is required by the group and thus is motivated by incentives and sanctions . Conversely, discretionary behavior is motivated by internal values and is seen as more cooperative and therefore ideal within a group . Depending on the procedural justice processes of the group, the social identity of the members will be influenced accordingly and different values will be emphasised . The more a member agrees with the type of procedural justice employed, the more they will identify with their group . This increased identification results in the internalization of the group's values and attitudes for the group member . This creates a circular relationship as the group's procedural justice processes will affect group members' levels of identification and, as a consequence, this level and type of identification will affect their own values of what is fair and unfair . This, in turn, will then affect how the individuals will engage with their group, with higher identification leading to discretionary and more desirable behavior . </P> <P> The idea of procedural justice is especially influential in the law . In the United States, for example, a concern for procedural justice is reflected in the Due Process clauses of the United States Constitution . In other common law countries, this same idea is sometimes called natural justice . </P>

Which of the following is not a determinant of procedural justice