I'm Dan and this is my blog. I'm a former high school math teacher and current head of teaching at Desmos. He / him. More here.


  1. Without doing the actual, you know, math, I’d say that the other thing this graph shows is that, overall, you had excellent attendance from your kids. Just from an eye-balling of it, I’d guess you had around 95-96% attendance. And that, in and of itself, is telling.

  2. Sort of.

    To what to do attribute the student with zero absences and the final grade in the high 50’s? Or the student with 13 absences and the grade in the 80’s?

    If there were something you could graph that had a high correlation to grades, what would it be?

  3. Dan, since you do objective quizzes and other assignments, what is the correlation of completion of work vs final grade look like? Furthermore, is that student with 0 absences but 50’s final grade one of those students who didn’t do all their work? And did the student with many absences but a passing grade do most or all of the work?

  4. I have a nearly identical graph about a single unit. It gave me a lot to think about.

    There are some kids that miss a lot of school and still do well – are they placed correctly? shouldn’t they be in regents rather than general? or is there something else going on in their lives that mean they need to be someplace where they can do well while missing school?

    There are some kids that come every day but still have trouble – where specifically is that problem? what can I do?

  5. I am interested in the number of students below 70%. Ballpark guess looks like 25%. Dan?

    This is where the data we need is lacking. Attendance has to be important to some degree but there are so many factors that could influence a bad or good grade. Re-taking the class, tutors, the class itself(remedial, etc), etc.

    I would love to have tools that we could use to collectively gather very detailed information about our students. We recently had a new baby and I was amazed at how much information they collect right in the room, on their touch screen computers. They pretty much had Jen’s entire life history, learning style(!), and medications at the touch of a button.

  6. The type of absence matters a lot here. There’s a wide gulf between my students that have 10 absences because of baseball games, or 10 absences because they had surgery, or 10 absences because they ditched class.

  7. This graph is too head-scratchingly weird for me to offer much analysis. 70% of my student’s semester grade, after all, is based on assessments that take up – max – 10% of our class time, so it’s conceivable, on the outer edge, that a student could be absent a great deal and still pass.

    The bummers are the ones who show up every day and look just as confused the fiftieth time I ask them to graph (-3, 4) as the first.

  8. I think that your assessment system would make grades a little less sensitive to occasional absences. At least, I found it helpful that this system automatically ensured that students who missed a quiz would be taking it several more times anyway without special arrangements for makeup tests. I also found that with grades that strongly hinged to test results, and without the option of curving tests to ensure decent class averages, I was pretty much forced to do more frequent reviews to improve class averages. That would also reduce the effects of absences.