Student outcomes.

Community colleges are an important entry point to postsecondary education for adults with no previous college education. Adults over the age of 25 represent more than a third of full-timeequivalent (FTE) enrollments at two-year public colleges, compared with 15 percent of FTE enrollments at four-year public colleges. While enrolled, older students are more likely than younger students to be working, married, caring for children, and less engaged with traditional-age classmates (Horn & Carroll, 1996). They are also more likely to attend part time, to enroll in an occupational rather than an academic program, and to seek an occupational certificate rather than pursue an associate degree or transfer to a fouryear institution (Bailey et al., 2003). These factors associated with older students negatively affect their enrollment patterns, enrollment intensity, and the probability of completing a degree (Choy, 2002). In fact, 60 percent of older first-time community college students, compared with 40 percent of younger first-time students, did not earn any credential or transfer after six years of enrollment, based on Beginning Postsecondary Students Longitudinal Study data. This gap in graduation and transfer rate probabilities could be better understood if we recognized how enrollment pathways (such as remediation) and enrollment milestones (intermediate outcomes such as attaining a certain number of credits) affect these educational outcomes and whether they affect older and younger students differently. Current research offers only a limited picture of the consequences of enrollment pathways and milestones. Studies show that timely credit attainment is important to degree completion, although such research has focused primarily on four-year college students (see, for example, McCormick, 1999). Other studies suggest that students who pass gatekeeper classes, such as remedial and initial college-level courses, have a substantially higher probability of earning a postsecondary credential. For many community college students, remediation or developmental education is a necessary part of the enrollment path (Adelman, 2006; Bailey & Alfonso, 2005). Yet, remediation might well have differential effects for younger and older students. A study of California community colleges found that for older students, as opposed to younger students, remedial classes were positively related to the probability of transferring to a four-year college or the receipt of a degree or certificate (Jepsen, 2006). Much recent research also exhibits a methodological weakness. While many studies use longitudinal data to shed light on factors that promote the educational attainment of college students, most look only at two points in time. First, when students start their postsecondary education, researchers collect a set of relevant covariates presumably associated with completion rates, like gender, race/ethnicity, socioeconomic status (SES), test scores, and institutional characteristics. After a given amount of time has passed to allow students to graduate, researchers again collect data to estimate the direct effect of these factors on some combination of policyrelevant educational outcomes, such as graduation, drop-out, persistence, or transfer. This strategy masks fundamental variation that could explain degree completion because factors such as enrollment patterns are likely to change over time. Event history modeling, or survival analysis, is a method specifically designed to study the occurrence and timing of events, thus enabling the measurement of the impacts of enrollment pathways and intermediate outcomes (or milestones) on some final outcome. Yet event history modeling is not prevalent in the higher NUMBER 32 OCTOBER 2006 ISSN 1526-2049