students across state lines and calculate college-going rates by state. These data are collected in even-numbered years. Age data — The age distribution of enrolled students offers insight into the relationship between the changing demographics of college-going cohorts and enrollment in different types of postsecondary institutions. They also permit detailed projections of enrollment by institutional type and by age. Because a student's dependency status is strongly related to age, the data can be used to provide estimates of the number of independent and dependent students attending postsecondary institutions. These data are collected in odd-numbered years. Unduplicated 12-month head count — Enrollment figures based on the unduplicated head count of students enrolled over a 12-month period is particularly valuable for institutions that use non-traditional calendar systems and offer short-term programs. Because this enrollment measure encompasses an entire year, it provides a more complete picture of the number of students these schools serve. Instructional activity — Data on instructional activity is measured in total credit and/or contact hours delivered by institutions during a 12-month period. Total entering class — Data on the number of incoming students (students enrolling for the first time in a postsecondary institution versus students transferring in from another postsecondary institution) at an institution. This measure permits the calculation of the graduation rate cohort as a proportion of the total entering student body. Student financial aid IPEDS collects data on the number of full-time, first-time degree/certificate-seeking undergraduate students who receive different types of student financial aid, including grants and loans, from different sources at each institution. IPEDS also collects data to show the average dollar amount of aid received by these students. Finally, as a result of the Higher Education Act (1965), as amended, IPEDS collects data to calculate the average net price at each institution for the following two groups: (1) full-time, first-time degree/certificate-seeking undergraduate students who receive grant and scholarship aid; and (2) full-time, first-time degree/certificate-seeking undergraduate students who receive Title IV federal student aid. Degrees and certificates conferred (completions) IPEDS collects data on the number of students who complete a postsecondary education program by type of program and level of award (certificate or degree). Type of program is categorized according to the Classification of Instructional Programs (CIP), a detailed coding system for postsecondary instructional programs. These data provide information on the number and location of completers by field. Business and industry, the military, and other groups