April 24, 2014


What is the 21st Century blackboard?

In the fall I’ll be back from the FTC and teaching again. I want to draw on the wisdom of FtT readers to help me figure out what technology I should be using to present material to students in the classroom. It’s a lecture class, teaching security and privacy to a class of 175 students, mostly computer science majors.

What should be my primary technology for presenting material?

In recent years I have preferred a technology called a “blackboard.” For those not familiar with this technology, it uses a large flat light-absorbing panel (the “blackboard”), across which I scrape a small cylinder of soft rock (“chalk”), leaving a residue on the board. I like the blackboard because it regulates my pace of presentation, because it allows students to see a lot of material at the same time, and because I can go back and modify / emphasize / point at material I have written. I like the physicality of the board — I am right there next to the board, the lights are on, and I can point at things for emphasis. (But I don’t like turning my back on the students while writing, nor the dust that gets on everything.)

I dislike canned PowerPoint style presentations for lecturing, because there tends to be less material visible to students at a time, because it gives me less opportunity to improvise in response to student questions, because it is less natural to refer to past material or emphasize a point, and ultimately because I think it pushes me toward an overly scripted lecturing style that conveys less nuance and enthusiasm for the material. I used to lecture with PowerPoint but for the last decade or so I have used the blackboard, and I think my teaching is better that way.

But it seems to me that there should exist a higher-tech approach that combines the advantages of the blackboard with the advantages of electronic media. I want something that I can use in an existing tech-enabled classroom, and that will scale up to a class of, say, 200 students.

What should I use? Please educate me in the comments.


  1. Phil Miller says:

    One of my best classes in undergrad saw the professor sit at the front of the lecture hall with a tablet PC hooked up to the room’s projector, drawing notes and writing theorems on that as he went. He would always post the full resulting file after lecture, for subsequent reference. Relative to a blackboard, it meant that he was never at a loss for ‘chalk’ in a variety of colors, he could duplicate things he’d already drawn in order to modify or elaborate on them, and that he could trivially swap his display from the written notes to other media, like video (often some random thing from YouTube during a break in the middle of class), animated demonstrations and visualizations of whatever he was teaching, or examples of how the material was applied in real settings.

    • Rick Wash says:

      I too use the blackboard for most of my lecturing. But recently, I purchased an AppleTV. This has the nice feature that you can very easily wirelessly mirror your iPad to the AppleTV. I’ve been thinking that I should try connecting my AppleTV to the projector in the classroom, and then use a stylus to write/draw on the iPad, which will then get mirrored on the big screen. Solves some of the readability-of-the-blackboard problems in a large classrooms. But I can still walk around carrying my iPad, and hand-write important things to help me keep pace and emphasize points.

    • Ed Felten says:

      Phil: Do you know which specific technology he used?

    • R says:

      All my lecturers do this, and it works wonderfully. (I think the university got a volume discount on hybrid laptop/tablets.)
      They mostly use Powerpoint (which has some annotation features built in), and use either blank slides or some kind of PDF Annotator when they need more room. Video recording of the entire thing also comes in very handy.

  2. Nick Coghlan says:

    One popular option is a free-form presentation tool like Prezi (http://prezi.com/), or an open source equivalent like Sozi (http://sozi.baierouge.fr/wiki/en:welcome) (The latter just uses a display path through an SVG file, while Prezi is Flash based).

    The nice thing about these is that you can put information in a broader context, zoom in and out for emphasis, etc.

    However, I suspect that would still suffer from the same pacing concerns you’re worried about with simple slide decks.

  3. Thomas Fors says:

    Take a look at how http://udacity.com is presenting their lectures.

    • Ed Felten says:

      The Udacity videos are interesting. Do you know which technologies they used to create them? It looks like some kind of electronic tablet, with a physical camera pointing at the tablet from above. (They also compress the action by skipping segments when the instructor is just writing out text or drawing diagrams–which would be difficult in live teaching.)

      These videos seem like an upgraded version of the Khan Academy method.

      • Thomas Fors says:

        No, I don’t know. The consensus in the discussion forums is that it’s a Wacom Cintiq 21UX tablet, but we don’t know how they’re compositing that with the shot of the hand and pen.

        In fact, one of the founders said Khan Academy was his inspiration for creating Udacity.

  4. Jim Lyon says:

    I tend to prefer the white board plus colored markers, plus the ability to project my computer image onto part of the whiteboard. Then, you can display media or other pre-canned stuff when you want to, and you can use your marker to write over the images to emphasize particular elements and so forth.

  5. timthelion says:

    I would sugest something where all the students can see the notes on their own computer screen. http://thecoccinella.org/
    This has the destinct advantage of allowing students with low vission to see the whiteboard as well as the rest. “”"”The prevalence of myopia has been reported as high as 70–90% in some Asian countries, 30–40% in Europe and the United States, and 10–20% in Africa.”"” https://en.wikipedia.org/wiki/Myopia#Epidemiology

    It also allows dissorganized/distracted students to easilly save your notes to their computers.

  6. Mitch says:

    What are you trying to accomplish by changing technologies? Nothing in your piece actually explains what you think the shortcomings of chalk on slate are…

    • Ed Felten says:

      I’m not at all certain that I’m going to swtich. I just want to see if there is something better. One drawback of blackboards is that I have to turn my back on the students a lot. I also worry that my handwriting could be more difficult to read in a larger classroom–which becomes more important in a larger class, like the one I’ll be teaching in the fall.

      I also have some hopes that digital technologies will have new advantages. For example, I can pre-prepare a diagram, or use standard icons to depict certain things, or capture a better record of what happened (better than blackboard photos taken in class), or …

  7. Anonymous says:

    Digital technologies only have the advantage that information is infinitely copyable. If you use a camera and a blackboard, that is possible too. So my advice would be to stick to the blackboard (I don’t know if chalk is environmentally friendly or not, but e-waste is certainly worse) simply let students make photos without flash or write a script/use a book for the material covered, so that students can use full-text search. Except for technical subjects were formulas and diagrams are used, I would prefer a speech lecture with a script.

    I’ve seen people use digital whiteboards and tablet PCs, but they are as bad as PowerPoint. One lecturer uses a combination of PowerPoint and a tablet PC and adds certain parts of the lecture by hand to the slides so that people have to attend the lecture (maybe he should ask himself why nobody comes). His handwriting is not tolerable on the tablet PC and you will have to print out the slides or use your laptop during lectures if you want to have complete notes. Another has bought a crappy digital whiteboard (from money they saved on staff!) and does something similar. Since nobody really asks questions and makes corrections (too often this is sadly necessary) except maybe two people or so (including me), there is no use case for adding further explanation on the slides or make notes to improve the slides (they use the same slides for the last decade).

    • Ed Felten says:

      In principle, digital technologies can have other advantages. For example, I could bring back a diagram from a previous lecture, or I could pre-prepare certain material, or capture a real-time record of what I showed/wrote/drew. Of course, all of this is available in principle, and not necessarily in a real system that I can get–which is why I’m asking folks about their experiences.

  8. B.E. Meister says:

    I too understand and appreciate your natural ease with a blackboard. There is something very communicative and emotionally expressive of the hand/chalk/friction/blackboard interactive “system”. Soft or thin; chalk-breakingly hard and/or vivid; made with the side or with the pointy bit: those chalk lines communicate more than mere text. It expresses your love for what you do, where you do it, and who participates in what you are communicating.

    No Powerpoint can work that magic. Even whiteboards fall short too. Too fussy, smelly and delicate.

    A smart, new stick of chalk at the beginning of a blackboard session is a physical promise. Treat it well it will last the session. Put a bit “boot’ in and it will snap. But NOT let you down. You can still use the bits and pieces. Dried or applicator compromised, whiteboard markers are natural betrayal of well-intentioned techno-replacements.

    My suggestion: (1) Keep the blackboard. (2) Take black&white images with a tripod-mounted device one device for each blackboard panel horizontally. (3) Compile the images into the lecture. (4) Create a “B&W reverse” analog image deck.

    Now the normal images are good for the usual stuff (PDFs, handouts…etc.). The b&w reverse for projection on white surfaces or inclusion with a white background presentation (PPT or what ever)
    Perhaps even photoshop the images for better contrast, thus allowing a projector of sorts to project over the real blackboard? Who knows.

    Thank you for opening the subject up. And: thank you the opportunity to allow others to comment.

  9. Thomas Fors says:

    I find the possibilities of the “whiteboard” app approach mentioned by timthelion above interesting. Especially allowing more students to answer a question simultaneously. But, I think it poses an extra requirement on the students which may or may not be feasible.

    You’re absolutely right about the advantages of being able to recall a figure from a previous lecture using a more digital technology. In addition to the udacity classes I’ve taken, I also have taken a number of coursera.org classes where they use a similar tablet setup (but they don’t do the fancy hand/pen superimposing). They frequently use prepared slides with type-written equations, tables, figures, etc. that they then augment during the lecture using the digital pen. This makes things more efficient since they don’t spend a lot of time drawing, and the prepared part of the slides are easier to read.

    In a live classroom setting, this has the disadvantage of the students not being able to keep up in note-taking unless a copy of the lecture material is provided for them (I guess it really depends on the individual student’s note-taking preference/skills). If you’re at all interested in providing recorded lectures to the students, I think that’s easier to do with the digital tablet model. You need screen capture software and an audio recording of the lecture. Recording a chalkboard lecture would probably require a camera operator since there’s probably movement to track.

    There’s an interview somewhere with Sebastian Thrun from Udacity who initially offered a Stanford Artificial Intelligence class both on-line using recorded lectures from a digital tablet and live in-class on the Stanford campus. He found that many of his in-class students stopped showing up because they preferred the recorded on-line version of him where they could rewind him and re-listen to key parts of his lecture.


    • Collin says:

      I wonder how interactive he is? I found that students who prefer that format are the ones that do not ask questions while students who have questions prefer to interact live.

  10. joe says:

    Ed, you need a document camera… allows you to face forward while you write on a sheet of paper. And you can still switch to a book or computer to show other things.

  11. Edmund says:

    An overhead projector such as the Califone OHP-2400 Open-Head Overhead Projector might be worth considering as a non-modern update on chalkboard. This allows you to face your audience, use multi-colored pens, erase mistakes (if you use the right pens), and go back to previous writings. It has a roll of transparency that you work your way through as you lecture, and you have a permanent record of what you wrote on that transparency. A disadvantage is that you probably need to darken the room lights to see the projected image. Also the resolution is not as high as chalkboard, at least with the typical pens available, and the available width is limited, so I wouldn’t recommend it for writing complex math equations.

  12. jbohn says:

    What we use in classrooms is the combination of iMac + Lumens document camera + Promethean interactive whiteboard; it’s the best of both worlds, as you can set up a presentation ahead of time, and annotate/edit it on the fly, at the board. The document camera allows presenting physical documents via the computer, with the same annotation ability.

  13. David Robinson says:

    Kahn Academy does a beautiful job (try watching one of the videos to see it in action). He uses a tablet, such that you can edit while facing the students. But, you also need a computer monitor within your field of view.

    See http://www.quora.com/Khan-Academy/What-hardware-or-software-can-I-use-to-make-videos-like-The-Khan-Academys

  14. Andrew McConachie says:

    I really like the paper53 App for my iPad. Ideally something like that could scale up for presentations. It works great for quick network diagrams.

    For presentations I have had good luck with smart boards. It allows you to project images from a computer desktop onto a screen and draw on it. Or you can just draw directly on the screen like a chalkboard.

  15. Steve Huston says:

    My calculus teacher in high school did something similar to what Edmund above suggested; she used a transparency projector with a roll of transparency material mounted to the bottom and stretched across to another spool at the top. She would write a page of notes, make sure everyone had copied up to that point and scroll it up (or only scroll up a little bit if the above was too complex). An advantage to this was that anyone was welcome to come to her room during non-class times and look at the roll to get notes they missed or go over something again, and if she wanted to recall something from before it was just a pull down of the sheet.

    Not at all what I’d consider 21st century, but it also only relies on some ink and a light bulb – hard to fail!

  16. Captain Nemo says:

    My wife has used an interactive whiteboard with some success. The software in use (“Activinspire”) installed and ran quite well on her laptop running Ubuntu 10.04.

    Using the “pens”, she could “draw” on the interactive whiteboard, with the images that were “drawn” projected onto the board by a projector. I can’t remember the brand of interactive whiteboard. I think the interactive whiteboard would function as both a screen and a traditional whiteboard.


    Another poster refers to these as “SmartBoards” instead of “interactive whiteboards”, but I think the term SmartBoard is a name used by a single manufacturer, not a name for the class of device.