I would be quite happy giving lectures with just a blackboard and a piece of chalk. At times I have threatened to give entirely oral lectures, though I'd probably be lynched if I actually tried it. I am not a great fan of educational technology. Each new communication technology has been hailed as revolutionizing education; each has been tried, and each failed to live up to its promise.
Another essay discusses my reservations regarding the use of transparencies, though I think that their existence can help stabilize course content. Besides those caveats, I just don't like staring into the bright light of an overhead projector and drawing on plastic with pens. But I probably would have continued to use them, with recourse to the board, except for a physical problem that caused me to rethink how I did presentations.
In 2001, I suffered a frozen right shoulder; my range of movement was severely limited, and lifting, reaching, or pulling were all painful. Though the severe effects were mitigated with a cortisone injection, some remain. I gave my fall 2002 course lectures using PowerPoint presentations on my Mac laptop plugged into the built-in data projector in the room I was assigned, with the occasional breakout to the board. For the final exam review, I solved problems on the board in real time, and my shoulder ached all weekend. It was clear that I was not going to be able to use the board for any substantial work.
I wasn't happy with PowerPoint; it is really only suited for business presentations with short, punchy points, and its handling of mathematics is atrocious. For my graduate course in winter 2003, I used a small portable data projector and a tiny Windows laptop, but I switched from PowerPoint to slides typeset using LaTeX, which handles mathematics very well.
There's not a lot of mathematics in the CS 251 slides, but they are already typeset using LaTeX, so I could have just used the same system. But the problem of the blackboard remained. Since I don't think slides are sufficient for all lecture presentations, I had built a number of blackboard digressions into the CS 251 slides when I revised them in fall 2001. I wasn't about to convert them to static slides.
I bought a Wacom Intuos2 graphics tablet, which is basically a two-dimensional sensing surface on which one "writes" with a magnetic pen. The device communicates via USB to a computer; if I plugged it into my laptop and the laptop into the data projector, the whole system could function as a rather expensive electronic blackboard. The bundled paint program, while overkill for my purposes, would work. However, Adobe Acrobat/Reader doesn't let one write onto presentations as PowerPoint does, so I had no way of annotating the prepared slides.
After some Web searching, I turned up a small Mac application called Desktastic, which lets one "write" on one's desktop. This is fairly useless on first glance, and in fact it had turned up in a Web site devoted to trashing idiotic Mac software. However, it is perfect for writing on top of presentations. I bought a registration code, and I was set, software-wise.
Here's what I had to do for my first trial run in the classroom, a few weeks before school started: turn the lights on, lower the rightmost of the three screens, move the desk on the raised platform at the front over to the right side (so the cables would reach), unsling my computer pack, take out the keys and unlock the podium (in which are stored the various controls for the A/V equipment, as well as a Nexus Windows workstation that one can use), power up the data projector, flip the Extron switch to "laptop", turn on the amplifier, go over to the desk, raise the podium built into it, unzip the pack, pull out the laptop coolpad and put it on the desk podium, pull out the Intuos tablet, take it out of its protective plastic, put it on the desk podium, pull out the VGA cable, connect it to the podium cable, pull out the audio extension cable, connect it to the podium cable, pull out the laptop, open it (it was sleeping, so it wakes quickly), connect the VGA and audio cables, move it onto the coolpad, connect the Intuos cable, open "Displays" on the laptop and detect the data projector, check the focus on the projector, and bring up the course slides on the laptop.
Whew! All that, with associated fumbling, took me more than ten minutes. It got better, and I didn't try to use all my options; for 341, I did try to use a remote slide advancer to avoid going to the machine constantly. That was necessary because of the physical setup of the room I was in then, with the podium off on the other side of the screen. For 251, the screen was on the other side of the room, and I could set up the desk next to the podium.
The setup is not ideal (my ideal would be three electronic blackboards replacing the chalk ones, where I could put up the slides sequentially and then "draw" on them with a featherweight wand) and the awkwardness does affect my lectures somewhat. If I want to break out and do some "blackboard work", I need to bring up a blank window on the laptop and draw on it. But then the slide is not visible. I have to go through the slides and decide which of them are worth duplicating onto transparencies. The desk with equipment on it blocks the leftmost screen (I can't get too far from the podium, the cables won't reach, and longer cables seem to make it hard for the data projector to sync) but I can use the centre screen, if I plan ahead and put the overhead projector on the first row of desks so that the image is big enough to be seen from the back. Clearly, this is an evolving set of techniques, and has to be rethought for different classroom geometries.
So how did it work, when I finally used it with students present? The physical setup worked all right, but my reaction to it somewhat surprised me. I had my instructor notes (only the nonblank ones, with some additional hand annotations) in a binder to the right on my desk, along with a copy of the course notes sold in the Bookstore. I hardly consulted those at all, but that I expected. What was surprising was that I didn't look at the laptop screen (which mirrors what is shown on the data projector) except when I was attempting to write on the screen with the tablet, and I didn't do much writing. Most of the time I spent over at the screen which was all the way to the left of the platform (from my point of view), gesticulating at it.
That meant a lot of walking back and forth, because the desk is all the way to the right so that the cables can reach the podium where the equipment is stored. I don't mind that -- I need all the exercise I can get, and it builds in natural pauses in the flow of information. This is one drawback with projected slides: there are no gaps. If I say something and then write it on the board, it takes fifteen or thirty seconds, and students can contemplate and digest it while they are copying it. If I say something and don't write it, I can't just pause for fifteen seconds; students will think I've slipped a gear. (I do pause like this when I see a potential pitfall or think of something new to say and have to work out the details, and students have complained about it in course evaluations.) Just as we shun dead air in radio and TV broadcasts, we are trained to shun it in a multimedia presentation.
Small problems on a more operational level can have a significant effect when dealing with such a setup. Partway through the term, I tried using Acrobat 5.0.5 (not Acrobat Reader) to present a lecture, and almost immediately ran into problems. The difficulty was that I was using a feature typically used to add brief "handwritten" comments to a PDF file, but I used it to try to draw on the slides as one would draw on an overhead transparency. If I paused a bit too long, Acrobat decided I was done, and turned what I've written into some sort of graphic object that cannot be edited except by an external editor (like, yikes, Photoshop). When that happened, and I paused in indecision, a voice from the audience: "Delete it," and I did. Then I realized that I had made a mistake in the replacement. "Switch to the other program," came the voice, and I obediently deleted every annotation and started up Desktastic, the crude but more flexible "draw on the screen" program. After that, things went much more smoothly. (This does mean that I can't switch to my much more portable Windows laptop -- a Fujitsu P2040, for those interested) because I can't find a Desktastic equivalent.)
I should have known better. Once I attended a conference on educational uses of the Web. Every presentation I saw had a technical glitch in it. Some were just annoying, like buttons not working or text being a little too small to read comfortably; some were fatal, like demos just not running. The only presentation that didn't have such a glitch was mine, because I was not using any electronic aids at all. I spoke from notes without slides or demos, mainly to prove a point about relatively low-tech approaches (the Web pages I was using, in a course where students posted their work and evaluated that of others, consisted entirely of text and links; showing them wouldn't have been of any use).
And now, having forgotten that point, I have put myself in the situation where if anything goes wrong in the complicated chain from prepared PDF file to laptop to Extron switch to data projector to screen, I have nothing to fall back on. I'd better start thinking of graceful alternatives, in case the voice isn't able to help me next time. --PR
(Adapted from blog postings made in 2003, September 2, 9, and 23.)