What is the appellate standard of review in a mixed fact matter?

The appellate standard of review depends on the nature of the matter being reviewed. These principles were established in Housen v. Nikolaisen, 2002 SCC 33. A pure question of law is reviewed on a standard of correctness and an appellate court is free to replace the opinion of the trial judge with its own. Findings of fact, on the other hand, cannot be reversed unless the trial judge made a palpable and overriding error. A question of mixed fact and law is subject to the standard of palpable and overriding error unless it is clear that the trial judge made some extricable error in principle with respect to the characterization of the standard or its application, in which case the error may amount to an error of law and the applicable standard is correctness.