This paper empirically contrasts the Jensen Measure, the Positive Period Weighting Measure, developed in Grinblatt and Titman (1989b), and a measure developed from the Treynor-Mazuy (1966) quadratic regression on a sample of 279 mutual funds and 109 passive portfolios, using a variety of benchmark portfolios. The study finds that the measures generally yield similar inferences when using the same benchmark and that inferences can vary, even from the same measure, when using different benchmarks. This paper also analyzes the determinants of mutual fund performance. Tests of fund performance that employ fund characteristics, such as net asset value, load, expenses, portfolio turnover, and management fee are reported. These tests surprisingly suggest that turnover is significantly positively related to the ability of fund managers to earn abnormal returns.