In statistical terms, transfer rates require two components: a numerator that represents community college students who transfer and a denominator that approximates the pool of potential transfer students. The California Task Force adopted a set of criteria to judge the appropriateness of prospective pairs of numerators and denominators. Its form was a four-pronged methodology that ranked measurement validity across both longitudinal and cross-sectional rates. Specifically, the four issues of validity were as follows: time equivalence; maturation validity; group equivalence; and construct validity. With these measurements at hand, the Task Force proceeded to evaluate a series of rates acquired from various practitioners. Instead of pursuing four different rates, the Task Force opted to restrict the operational definition of transfer students to first-time freshmen at community colleges. Since some students were incorrectly perceived as having transfer potential, and some students with transfer potential could go undetected, the strategy was to devise two transfer rates which represented alternative but complementary points of view. The first rate summarized the transfer activity of first-time freshmen at community colleges who earned a minimum number of six transferable units in their first fall term, while the second rate added the subjective criterion of students who also stated at entry that their educational objective was to transfer. The two longitudinal methods for computing transfer rates were very resistant regarding errors or biases associated with sampling, data collection, and measurement error. (JMC)