Feedback From Computers Doesn’t Have To Be Boring

David Cox sent his students through Function Carnival where they tried to graph the motion of different carnival rides. (Try it!)

Every student’s initial graph was wrong. No one got it exactly right the first time. But Function Carnival doesn’t display a percent score or hint tokens or some kind of Bayesian probability they’ll get the next graph right. It just shows students what their graph means for that ride. Then it lets them revise.

David Cox screen-recorded the teacher view of all his students’ graphs. This is the result. I love it.

BTW. I’m hardly unbiased here, having played a supporting role in the development of Function Carnival.

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. I tried function carnival recently and overall it was a good experience, but there was one issue with the setup which I felt was counterproductive.

    A large number of students figured out how to “cheat” in the sense that if they drew very slowly they could just match their image to the actual one. This required no reflection at all on what or why they were doing what they were doing. I felt this short circuited the task, and so it would have been stronger without this ability. I know this is built in right now to the “immediate feedback” idea, but maybe there is a compromise somewhere?

  2. @James: head over to

    @David: great feedback. We’ve seen this too sometimes. Just for clarity — was the “cheat” just overusing the “preview while drawing” feature? For example, moving the time scrubber a bit, matching height, and dropping a dot? Or was it that they’d draw little snippets of graph, play it out, and then correct just the very end?

    For some of the velocity versions we’re building, preview isn’t possible anymore (mitigating the first “cheat”). Curious how that feels. Here’s an example with the Cannon-man velocity:

  3. @Eli: I think it was the first option – preview while drawing. They were a motivated bunch of students, but they were also competitive – they really wanted “their” graph to be the one that came up as “extremely precise” at the end phase.

    I looked at the link you posted and it does make it harder to do what they did, but they can still move the slider a little at a time to try and match it up.

    I’m not really sure how to get around this completely. Perhaps some way for some of them to gather more detailed information from the “real” version, and then have to commit more to their own version. The detailed data can be some kind of access to more detailed time and height information – but I’m not sure how to implement this without causing other issues.

  4. This is a wonderful tool! As a long-time Physics educator who believes that a deep understanding of velocity vs. time graphs is the key to a solid and robust comprehension to all things first-semester 9-12 Physics, this is an exciting program! I like that the students are giving constructive feedback to re-think and re-work their graphs, and are not just given the answer. Non-boring feedback indeed!

  5. I had a great time doing this activity in class.
    I tried it with 2 groups, the first few students got the “cheating” idea- they moved the time line and marked dots, and then draw a line between the dots. But, I’ve noticed that the cheating required some understanding. Students that were completely wrong didn’t understand the cheating.

    I gave my 9 years old kid to play with this, and she did a big mess on the screen just to see lots of blue cars bumping each other :-)

  6. Hello, I wish to make a question.
    I really liked of this activity, but i’m worried. There is a way to use this offline?
    I’m afraid ’cause imagine I prepared my lesson and then I get in the class see that page is not more avaliable.
    Thks for help!
    Lucas. Rio de Janeiro, Brasil.