capricious

Given to sudden and unaccountable changes of mood or behavior.

A standard for review for appeal, often seen in administrative law.  Under this standard, the finding of a lower court will not be disturbed unless it has no reasonable basis - if the judge makes a decision without reasonable grounds or adequate consideration of the circumstances.

Although there is no set standard for what is an arbitrary and capricous decision, guidance can be found in Natural Resources Defense Council, Inc. v. United States EPA, 966 F.2d 1292, 1297 (9th Cir. 1992).  "5 U.S.C. § 706(2)(A) (1988) authorizes the court to "set aside agency action ... found to be ... arbitrary, capricious, an abuse of discretion, or otherwise not in accordance with law." Under this standard a court must find a "rational connection between the facts found and the choice made." Sierra Pacific Indus., 866 F.2d 1099, 1105 (9th Cir.1989) (citing Motor Vehicle Mfrs. Ass'n v. State Farm Mut. Auto. Ins. Co., 463 U.S. 29, 43, 103 S.Ct. 2856, 2866, 77 L.Ed.2d 443 (1983)). The court must decide whether the agency considered the relevant factors and whether there has been a clear error of judgment. Citizens to Preserve Overton Park, Inc. v. Volpe, 401 U.S. 402, 416, 91 S.Ct. 814, 823, 28 L.Ed.2d 136 (1971)."