The essential requirements of procedural fairness are fairness and detachment. Those requirements find expression in the two rules of procedural fairness. The first is the hearing rule (audi alteram partem), which is the requirement to give notice to the person affected by a decision that a decision is to be made, to disclose information or material on which the decision maker proposes to rely, and to allow an opportunity to put a case. The second is the rule against bias (nemo debet esse judex in propria sua causa), which is the requirement that the decision maker be free of actual bias or prejudgment, or the perception of prejudgment.

The hearing rule is a broad topic that could potentially cover a vast range of procedural requirements that arise from the principles of procedural fairness. This chapter addresses four aspects of those requirements: (a) the application of the hearing rule; (b) the exclusion or limitation of the hearing rule; (c) the content of the hearing rule; and (d) the consequences of breach of the hearing rule.

It is important to note at the outset that the term ‘hearing’ does not refer just to that part of a decision-making process that may take the form of an oral presentation of evidence and argument. Unlike judicial decision-making in an adversarial system, which has its primary focus on the formal oral hearing of evidence and submissions, administrative decision-making adopts many forms, and need not necessarily involve an oral component.