What's a "Cohort"

Cohort: A statistical grouping of students based on the year they entered ninth grade.

Who comprises the original cohort for the class of 2008?

• Students who were enrolled in Virginia public schools in 9th grade in the 2004-2005 school year and who were coded in the VDOE Student Record Collection as first-time 9th-grade students.
• Students who transferred into Virginia public schools in 10th grade during 2005-2006.
• Students who transferred into Virginia public schools in 11th grade during 2006-2007.
• Students who transferred into Virginia public schools in 12th grade during 2007-2008.

How are students in the cohort tracked?
Each individual student's status is tracked over time and throughout the Virginia public school system using his or her unique state-testing identifier maintained through the commonwealth's Education Information Management System. The identifiers allow the state to follow students as they transfer in and/or transfer out of Virginia public schools.

• Students who transfer out of Virginia public schools are removed from the cohort based on their exit codes.
• Students who transfer in to Virginia public schools for the first time from outside the public school system are assigned to a cohort based on the year and grade in which they first entered a Virginia public high school (grades 9-12).
• Students who are incarcerated will be counted as transfers as they leave and re-enter the system.
• Incarcerated students who re-enter Virginia public schools will be assigned to a cohort based on the year and grade at the time of return to public school.

The original graduation cohort of 2008 was defined using data from the end-of-year student record collection in 2004-2005. That was the first time Virginia collected unique identifiers for all students in the public school system. At that point in time, and during each subsequent data collection window (annually for fall, spring, end-of-year and summer), VDOE updates each student's status to record his or her most recent data, including the following for all students in the cohort:

• Whether they are actively enrolled Virginia public schools;
• The most recent division and school where enrolled;
• The most recent subgroup data including race/ethnicity, gender, disability status, disadvantaged status and LEP status;
• Students' graduation status, and - if applicable - year diplomas awarded;
• Students' completion status, and - if applicable - year of alternative credentials;
• Exit code and date - if applicable;
• Whether the student has died; and
• Transfer status - if applicable.

To include summer graduates, the final status update for all students in the original cohort took place after the summer 2008 data collection.

Students who graduate in fewer than four years are counted as on-time graduates and are included in the graduation rate calculated for their original ninth-grade cohort.

The on-time graduation rate includes only those students who graduated from high school within four years of entering ninth grade. It does not include:

• Students who took longer than four years to graduate;
• Students who earned their GED_® or
• Students who earned certificates of completion.