The clearly erroneous test is a test used by appellate courts when reviewing a holding by a lower court. The test, established by Rule 52(a) of the Federal Rules Civil Procedure, states that fact findings by a judge in a nonjury trial stand unless clearly erroneous and the reviewing court must give due regard to the trial court's opportunity to judge the witnesses' credibility.
In the United States v. United States Gypsum Co. the Supreme Court stated that the Federal Rule of Civil Procedure 52(a) provides that “a finding is ‘clearly erroneous’ when although there is evidence to support it, the reviewing court on the entire evidence is left with the definite and firm conviction that a mistake has been committed.” Essentially, the appellate court must determine that a finding is unsupported by substantial, credible evidence in the record to meet this standard.
[Last updated in July of 2022 by the Wex Definitions Team]