the discretion of any board, tribunal or officer, when the act complained of is either judicial or quasi-judicial unless it clearly appears that there has been an abuse of discretion on the part of such Court, board, tribunal or officer, and in accordance with this rule mandamus may not be invoked to compel the matter of discretion to be exercised in any particular way. This principle applies with full force and effect, however, clearly it may be made to appear what the decision ought to be, or even though its conclusion be disputable or, however, erroneous the conclusion reached may be, and although there may be no other method of review or correction provided by law. The discretion must be exercised according to the established rule where the action complained has been arbitrary or capricious, or based on personal, selfish or fraudulent motives, or on false information, or on total lack of authority to act, or where it amounts to an evasion of positive duty, or there has been a refusal to consider pertinent evidence, hear the parties where so required, or to entertain any proper question concerning the exercise of the discretion, or where the exercise of the discretion is in a manner entirely futile and known by the officer to be so and there are other methods which it adopted, would be effective."
