High school A secondary school offering the final years of high school work necessary for graduation, usually including grades 10, 11, and 12 (in a 6-3-3 plan), or grades 9, 10, 11, and 12 (in a 6-2-4 plan). Full-time enrollment The number of students enrolled in higher education courses with total credit load equal to at least 75 percent of the normal full-time course load. Secondary school Senior high school A secondary school offering the final years of high school work necessary for graduation. Part-time enrollment The number of students enrolled in higher education courses with a total credit load of less than 75 percent of the normal full-time credit load. 4-year institution An institution legally authorized to offer and offering at least a 4-year program of college-level studies wholly or principally creditable toward a bachelor's degree. Postsecondary education The provision of formal instructional programs with a curriculum designed primarily for students who have completed the requirements for a high school diploma or equivalent. Secondary instructional level The general level of instruction provided for pupils in secondary schools (generally covering grades 7 through 12 or 9 through 12) and any instruction of a comparable nature and difficulty provided for adults and youth beyond the age of compulsory school Private institution A school or institution that is controlled by an individual or agency other than a state, a subdivision of a state, or the federal government. Associate's degree A degree granted for the successful completion of at least 2 years (or the equivalent) of full-time college-level study. This term includes degrees granted in a cooperative or work-study program. Enrollment The number of students registered in a given school unit at a given time, generally in the fall of a year.