The indicators in this section of The Condition of Education report trends in enrollments across all levels of education. There are 16 indicators in this section: 11, prepared for this year's volume, appear on the following pages, and all 16, including indicators from previous years, appear on the Web (see the List of Indicators on The Condition of Education website in the Contents section for a full list of the indicators). Enrollment is a key indicator of the scope of and access to educational opportunities and is a basic descriptor of American education. Changes in enrollment have implications for the demand for educational resources, such as qualified teachers, physical facilities, and funding levels, which are required to provide a high-quality education for our nation's students.

The indicators in this section are organized into an overview subsection, which is made up of an indicator on enrollment rates reported by age group, and a series of subsections organized by level of the education system. These levels are preprimary education, elementary and secondary education, undergraduate education, graduate and professional education, and adult education.

The indicator in the first subsection compares rates of enrollment in formal education programs across certain age groups in the population. Looking at trends in the enrollment rates of individuals provides a perspective on the education of the U.S. population at different points in the life cycle and over time.

An indicator on the website describes participation in center-based early childhood care and education programs, such as Head Start, nursery school, and prekindergarten, which can help to prepare children for elementary school and can also serve as child care for parents. Two of the indicators on the following pages present aspects of family involvement in cultivating certain developmental areas in the preprimary years, which also plays a role in preparing children for formal education. Elementary and secondary education provide knowledge and skills that prepare students for further learning and productive membership in society. Because enrollment at the elementary and secondary levels is mandatory in most states until at least age 16, and in a number of states until age 17 or 18, changes in enrollment are driven primarily by shifts in the size and composition of the school-age population, as well as by shifts in the types of schools students attend, including public schools, private schools, and homeschooling. These factors are examined in indicators on the following pages. Postsecondary education offers students opportunities to gain advanced knowledge and skills either immediately after high school or later in life. Because postsecondary education is voluntary, changes in total undergraduate enrollments typically reflect fluctuations in enrollment rates and the perceived availability and value of postsecondary education, as well as the size of college-age populations. Graduate and professional enrollments constitute an important segment of postsecondary education, allowing students to pursue advanced coursework in a variety of areas. Indicators on postsecondary enrollment are found in this volume. An indicator on the Web describes adult education, which includes formal education activities in which adults participate in order to upgrade their work skills, to change careers, or to expand personal interests.

Some of the indicators in these subsections provide information about the characteristics of the students who are enrolled and, in some cases, how enrollment for different types of students varies across schools. For example, indicators that appear in this volume describe the racial/ethnic distributions of public school students, the number and characteristics of children who speak a language other than English at home, and the number and percentage of children with disabilities.

The indicators on participation in education from previous editions of The Condition of Education, which are not included in this volume, are available at http://nces.ed.gov/programs/coe.