Type I and Type II errors

Type I errors, or false positives, are errors of commission where the status quo is incorrectly rejected in favor of new, misleading information. e.g. convicting an innocent defendant.

Type II errors, or false negatives, are errors of omission where a misleading status quo is allowed to remain due to failure in identifying it as incorrect. e.g. failing to convict a guilty defendant.

Type I errors are often said to be worse than type II errors, but in practice it depends. Mostly depends on the potential consequences of each error case.