discriminant function
discriminant function (di-skrim-[schwa]-n[schwa]nt). An IRS method of selecting tax returns to be audited. • The method consists of (1) using a computer program to identify returns with a high probability of error (such as those showing a disproportionate amount of deductible expenses), and (2) having examiners manually review the selected returns to determine which ones should be audited. — Also termed DIF system. [Cases: Internal Revenue 4443. C.J.S. Internal Revenue §§ 616, 618.]