• Baseline survey of high school sophomores, in spring term, 2002.
• Cognitive tests in reading and mathematics.
• Questionnaires administered to parents, math and English teachers, school principals, and heads of the school library media center.
• Sample sizes:
  • 750 schools (questionnaires: principals, head librarians or media center directors; facilities checklists completed by survey administrators)
  • over 15,000 students and their parents
  • mathematics and English teachers
• Schools selected first, then tenth-grade students selected randomly within each school.
• Non-public schools(specifically, Catholic and other private schools) sampled at a higher rate, ensuring that sample is large enough to support comparisons with public schools.
• Some types of students from less numerous population groups—for example, Asian Americans—selected at higher rates so that the study can be used validly to compare the experiences of African Americans, Asians, Hispanics and Whites.

• Follow-up in 2004, when most sample members were high school seniors, but some were dropouts or in other grades.
• Student questionnaires, dropout questionnaires, cognitive tests, school administrator questionnaires administered.
• Students from the Base Year sample:
  • Those still in the 750 schools included in the Base Year sample.
  • Those in the Base Year sample who had transfered to a different school.
• Dropouts from the Base Year sample
• Also, a "freshened" sample of spring term 2004 seniors who were not sophomores in 2002.
• ELS:2002 began with a representative sample of high school sophomores. For ELS:2002 to also contain a fully representative sample of high school seniors two years later, the base year cohort was "freshened." What freshening means is that spring term 2004 seniors who were not sophomores in the U.S. in spring term of 2002 (for example, students who were out of country, or in another grade sequence because of skipping or failing a grade) were given a chance of selection into the study.
• Thus, the First Follow-up sample both continues the longitudinal sample of spring 2002 sophomores and represents all the nation's spring term 2004 high school seniors.

• High school transcripts are being collected for all students who were last enrolled in their Base Year school in the spring 2004. The transcripts provide school archival records on courses completed, grades, attendance, SAT/ACT scores, and so on from grades 9 through 12.

• Follow-up in 2006, when many sample members will be in their second year of postsecondary education. Others will be employed and have not attended any schooling after high school. Some who previously dropped out of high school may have earned a General Education Development (GED) or other equivalency certificate or be working on a GED.
• All sample members who were respondents in the Base Year and/or the First Follow-up will be included.
• Survey information will be obtained from sample members by a web-based self-administered interview; computer-assisted telephone interview; or computer-assisted personal interview.

One or more additional follow-ups may be conducted starting four or more years after the Second Follow-up. Most likely, there will be one more follow-up, six years later. In the last follow-up, postsecondary institution transcripts will be obtained.