What is 'standard of review' and how does it affect my chances on an Ontario appeal?

Standard of review describes how closely an appeal court will scrutinize the decision being appealed, and it generally depends on what kind of error is being alleged. For a genuine question of law, an appeal court generally reviews the lower court's conclusion on a "correctness" standard, meaning it can substitute its own view if it disagrees, without needing to show the original judge made an obvious mistake. For findings of fact, or mixed questions of fact and law that can't easily be separated, appeal courts generally apply a much more deferential standard, intervening only where there's a clear and significant error, not merely a different view of how the evidence could have been weighed.

This distinction matters enormously to how realistic an appeal actually is. An appeal built around "the judge got the law wrong" faces a meaningfully lower bar than one built around "the judge should have believed a different witness" or "the judge weighed the evidence incorrectly," since factual findings from a trial judge who actually heard the evidence are given considerable deference. Understanding which category your grounds for appeal genuinely fall into, before committing to the cost and effort of an appeal, is one of the most important early steps in assessing whether an appeal is realistically worth pursuing.