October 8, 2005

Age-specific graduation rates

After too many months, I've finally carved out a few hours to play with the data Florida's DOE sent me, a collection of individual-level data on enrollment, age, grade level, sex, race/ethnicity, lunch status, and withdrawal code (including different types of diplomas). The data isn't clean (especially when looking at the birth years), but it's important to see what can be done with the different file structures, and an initial, very draft and obviously not quite accurate graph of age-specific graduation rates is instructive:

grate_10-5-05.gif

(Click picture for larger version. PDF version of graduation-rate graph is also available.)

(For those not used to event-exposure rates, the rates over 1 are not errors. An event-exposure rate has the denominator of the collective exposure to a certain event, usually measured in person-years. So if an eighteen-year-old graduated two months after her birthday, she only added a sixth of a year (0.1666... person years) to the total exposure. If a majority of 18-year-olds in school graduate, and they only contribute on average half a year of exposure, then the rate is going to be over 1.)

There are a few notable patterns. First, the non-standard diplomas become an important feature only with 19-year-olds and those older. In other words, most people don't get either GEDs or attendance certificates until after 19. Second, the bump at age 22 (and the increasing gap between standard and other diplomas) is from the small number of students with disabilities who receive services until the end of the school year after they turn 22.

More work needed... much more work. But it's time this weekend to turn to other tasks in EPAA and grading. Listen to this article
Posted in Research on October 8, 2005 6:19 AM |