In Defense Of Digital Media

Jason Dyer, responding to my NLOS cannon post:

Since I’ve done this over the summer with real life bottle rockets, a launcher that could be set at any angle, and a vertical target, I’m not finding the computerized version nearly as interesting. I’ve also run a simpler version of this in my classroom with wads of paper. Why must everything be digital? [emph. added]

Hopefully I’ve made clear by now my preference for pedagogy over technology. If digital media makes for inferior learning, then, by all means, let’s stuff it in a burlap sack and toss it in the river. My preference is also for the real thing over a digital simulation of the real thing. That said, there are three circumstances where digital media is preferable to the real thing:

  1. The real thing is too expensive. I’d rather let every kid hold a photo of a measuring cup than spend $100 for a class set of measuring cups. It’s too expensive to take a class trip to the Yucatan Peninsula so perhaps we can forgive ourselves for showing photos of the Mayan pyramids instead. I’d much rather copy and paste Google’s satellite imagery into a Keynote presentation than charter a plane to take my kids up in groups.
  2. The real thing is too mathematically noisy for classroom use. Jason prefers a real demonstration of projectile motion using bottle rockets to my use of online simulators but that introduces acceleration and wind resistance— mathematical noise — into the system. Let’s not romanticize the real or the digital. They are both deficient. They both require a cost-benefit analysis.
  3. The real thing can’t be iterated precisely enough. I wanted to show my students several misses with “Will it hit the can?” — long, short, and to the side — and at least one success. If my students were live with me, on the scene, they would see many, many, many misses, most of which would be mathematically unhelpful. My students can also measure and manipulate digital media (by modeling a parabola in Geogebra, tracking motion in Logger or Tracker, etc.), something they can’t do with live events.
I'm Dan and this is my blog. I'm a former high school teacher, former graduate student, and current head of teaching at Desmos. More here.


  1. Jason Dyer

    April 26, 2009 - 2:18 pm

    Re #1, of course, but let me pick at your particular example and say I’ve found some at the dollar store before. If all you’re doing is unit conversion I don’t see the point of having the actual artifact, but I wanted to mention that in case you need them in the future.

    Re #2, that’s where I dig my heels. I think the noise makes the experiment more valuable, not less. Even asking students to measure angles with a protractor racks up a significant error over time. Should a percent error stop us? The experience of jumping off from the neat equations and diagrams of mathematics is invaluable, and can be a source for future mathematics as students try to come up with methods for reconciling with problems.

    I have had a student tell me hated math until he got to my class, because we grappled directly with the issues mentioned at #2 above.

    Re #3, no argument here (although you really ought to try the marble experiment at least one — you’ll be surprised at the repeatability).

  2. Andrew Ziobro

    April 27, 2009 - 4:57 am

    I agree that having students learn to deal with noise is extremely valuable. Being able to explain or figure out why the math they know doesn’t seem to work is very important. But sometimes it is difficult to get through all the noise in the time restrictions of a class. Getting students thinking about error in measurement is extremely valuable for life outside the protection of the classroom. Getting them to think of ways to reduce error in measurement. Getting them to realize how accurately they need to measure. Is the closest inch good enough? Why?

    I am going to try to tie this back to the students science classes. How do your science teachers deal with this concept? Where does error analysis fit in your school?

  3. A. Mercer

    April 27, 2009 - 7:51 pm

    Can I take this down to the primary grades? During a conversation on It’s Elementary show (, two die-hard constructivist/constructionist type teachers were talking, Maria Knee and Colleen King. These folks do Logo and robots with kinders, that is how hard core they are. They were discussing online vs. real math manipulatives. Both used to HATE the idea of online manipulitives, and thought the kids would have to “physically” handle them (ala Montessori) to understand and use them, but they’ve come to the conclusion that virtual manipulatives are just fine. The kids move them around and use them, and derive meaning from them.

  4. Dave Bonar

    April 28, 2009 - 11:52 am

    As a physics teacher I want the real life lack of neatness for at least two reasons.

    1. Often it can spark great discussions about why our real lab results are not as perfect as the mathematical models. As Jason implied above it can also work in reverse. Sometimes my students are amazed at how close we can get using such simple tools.
    2. I appreciate the challenge of designing challenges or labs that can be done with simple equipment while still obtaining good results. So kids think its cool. Others would clearly prefer to either digitally simulate the lab or at least automate the data collection.

    Of course after we take the data I have the students use Excel (or Logger Pro) to fit the curve and determine, determine relationships, and ultimately derive the main laws.

  5. Online Educator

    May 10, 2009 - 1:13 pm

    I’m working on a science curriculum K-8 which is ….digital. While I’ll have lots of experiments that could be performed in the real world and there will be lots of explanations that will evoke real world prior knowledge, the program will not be a blend.

    The program will be built so that the students “discover” knowledge and the scientific process through software, simulation, data, and video. No textbook, only supplementary experiments. More heretical than that, the curriculum will allow for teacher-led teaching. It will allow for online group discussion. But, at it’s core, it’ll be student-paced all digital learning.

    Of course, much of the scientific establishment explains to me that this is a bad idea. It is suboptimal. It’s WRONG.

    I’m not much for explaining why but I think that I can make a curriculum that will do a great deal of good in teaching science and building enthusiasm for it, but since I come out of a decade of developing video games (I’ve gone platinum as a producer), I think I have a few insights into engaging kids in an interactive process of discovery.

    So I enjoyed your post.

    founder of,,
    (PS – don’t get too excited. this is a self-funded activity. It’ll take years!)