The educational effectiveness of community colleges is under new scrutiny as a result of both a federal government focus on accountability of higher education institutions and greater competition for the state funds traditionally directed to the colleges. Policymakers, who want to tie public college allocations to their outcomes, and families, who are investing sizeable amounts in increased community college tuition, want assurances that the colleges will provide educational returns that justify their cost. Community colleges must collect and report graduation and transfer rates, based on the outcomes of fall semester cohorts of first-time, full-time students in degree programs, to meet the requirements of the Student Right-to-Know and Campus Security Act (1990). Current convention is to use these Student Right-to-Know (SRK) data as the measure of a college's effectiveness, and they indicate that completion rates are very low for community colleges overall. Indeed, more than half the students who enroll eventually leave without a credential. But the value of SRK data as appropriate measures for outcome-based accountability is disputed by college advocates, who assert that they are not accurate reflections of student success for a variety of reasons. This Brief summarizes research conducted by the Community College Research Center that used data on student characteristics and educational outcomes from several federal government sources to explore the legitimacy of the various ways that college effectiveness can be assessed by using measures of student success. It takes account of the sometimes competing measurement preferences of the interested parties and identifies the strengths and weaknesses of each.