This report examines the four-year cohort graduation rates in Vermont by geography and school year. In the mid-2000s, there was a national shift from an event graduation rate to the four-year cohort graduation rate, prompted by No Child Left Behind Act (2001). The event graduation rate is the percentage of high school students who graduate during a single school year while the four-year cohort graduation rate is calculated by tracking students from the time they enter grade nine. Since school year 2005-2006, Vermont has collected the four-year cohort graduation rate for accountability purposes and to develop strategies such as flexible pathways to graduation and proficiency-based learning. 

Data used in this report were acquired from the Vermont Agency of Education (AOE). The four-year cohort graduation rate is the percentage of students enrolled at a high school who graduate within four years of entering ninth grade. Graduates are those earning high school diplomas. Students earning high school credentials by passing General Educational Development (GED) tests are not considered graduates for the purpose of this definition. Students who transferred out of a high school or are deceased are excluded.

While event graduation rate data, or the percentage of high school students who graduate during a single school year, is available from 1990 onward, it is a less sophisticated measure of high school graduation rates. The report includes high school students from all public high schools in Vermont, but not the four historical academies: Burr & Burton, Lyndon Institute, St. Johnsbury Academy, and Thetford Academy.

Values between 1 and 10 (inclusive) were suppressed/removed for a given geography and replaced with the value ‘-999’ or ‘-999.00%’. Secondary suppression occurred in instances where a data element could be used to calculate a related value that was suppressed (e.g., when a numerator was suppressed for a calculation, the denominator and resulting value from the calculation were suppressed). When suppression of one case within a group of cases (e.g., graduation count for a single high school for a year) could result in reverse calculation of suppressed values, secondary suppression was applied to the next case with lowest value (e.g. the high school with the next lowest graduation count was suppressed for the same school year). The suppression rules were enforced to prevent the identification of individuals in an effort to preserve privacy and confidentiality.

The high school cohort graduation rates were calculated using the following formula:

([High School Graduation Cohort Count for the School Year] / [Ninth Grade Cohort Count]) * 100

The high school cohort includes students from the time they enter grade nine to graduation. Students who graduate within four years are considered on-time graduates. Students who transfer into a school are included in the cohort, while students who transfer out are dropped from the cohort.

Four-year cohort graduation rates at the high-school level must be interpreted with caution due to small sample sizes in many instances. The report does not explain how or why four-year cohort graduation rates may or may not differ over time or between schools. It also does not draw conclusions on the reasons for differences in educational attainment within each cohort.