Ottawa (City) v. Coliseum Inc., 2016 ONCA 363:
 The standard of review on appeal from a commercial arbitration award will generally be reasonableness. The leading case is Sattva, wherein Rothstein J. said, at para. 106:
In the context of commercial arbitration, where appeals are restricted to questions of law, the standard of review will be reasonableness unless the question is one that would attract the correctness standard, such as constitutional questions or questions of law of central importance to the legal system as a whole and outside the adjudicator's expertise.
 The reason for this deferential standard, even in appeals that are restricted to questions of law, was explained by Rothstein J. in Sattva, at para. 104:
Appellate review of commercial arbitration awards takes place under a tightly defined regime specifically tailored to the objectives of commercial arbitrations and is different from judicial review of a decision of a statutory tribunal. For example, for the most part, parties engage in arbitration by mutual choice, not by way of a statutory process. Additionally, unlike statutory tribunals, the parties to the arbitration select the number and identity of the arbitrators.
 In a similar vein, in Popack v. Lipszyc, 2016 ONCA 135, 262 A.C.W.S. (3d) 841, Doherty J.A. linked the fact of a private consensual arbitration with the need for judicial deference to the result of that arbitration in this fashion, at para. 26:
In addition to the generally applicable principles that urge deference in the review of all discretionary decisions, the nature of the specific order under appeal can also enhance the deference rationale. The application judge exercised her discretion in the context of a review of an award rendered in a private arbitration before a panel chosen by the parties to determine the dispute between them. The parties' selection of their forum implies both a preference for the outcome arrived at in that forum and a limited role for judicial oversight of the award made in the arbitral forum. The application judge's decision to not set aside the award is consistent with the well-established preference in favour of maintaining arbitral awards rendered in consensual private arbitrations. [Emphasis added, citations omitted.]
 There is nothing in this appeal taking it outside the general rule that judicial review of a commercial arbitration award is conducted on a reasonableness standard. This appeal does not deal with constitutional questions or questions of law of central importance to the legal system as a whole and outside the adjudicator's expertise.
 In my view, Dunsmuir v. New Brunswick, 2008 SCC 9,  1 S.C.R. 190, remains the leading case on the definition of reasonableness. Bastarache and LeBel JJ. stated, at para. 47:
Reasonableness is a deferential standard animated by the principle that underlies the development of the two previous standards of reasonableness: certain questions that come before administrative tribunals do not lend themselves to one specific, particular result. Instead, they may give rise to a number of possible, reasonable conclusions. Tribunals have a margin of appreciation within the range of acceptable and rational solutions. A court conducting a review for reasonableness inquires into the qualities that make a decision reasonable, referring both to the process of articulating the reasons and to outcomes. In judicial review, reasonableness is concerned mostly with the existence of justification, transparency and intelligibility within the decision-making process. But it is also concerned with whether the decision falls within a range of possible, acceptable outcomes which are defensible in respect of the facts and law.
Of the Law Societies of Upper Canada and Nunavut