During my spring visit to University College London I saw a piece of hardware in almost all the classrooms that I’d never seen before: a WolfVision Visualizer. I saw Marcos Vera teach his development class with it and I heard Wendy Carlin rave about it when I talked to her about teaching introductory economics. I was shocked to realize how similar lecturing with a visualizer is to how I’ve been lecturing with my iPad Pro.

The Visualizer looks like an old-school overhead projector, but it’s actually a modern digital video camera that projects whatever you put under it onto a big screen–There’s no need for transparencies. When working through math, I watched Marcos put a piece of paper under the Visualizer and start writing with a pen or marker. When he reached the bottom, he gently slid the paper up, put down a new piece of paper, and kept writing. It was easy for him to refer to earlier work by just bringing back previous pieces of paper. A few times he annotated a printout of a slide where he had left some empty space.

There are big advantages of this approach over writing on a whiteboard. Everything can be easily recorded–At UCL they use Lecturecast technology that also records audio and I believe video from the back of the room. What the instructor writes is legible by everyone in the room and the whole system requires very little physical space if you’ve already got a screen and a projector.

The Visualizer also has a few advantages over what I’m doing with the iPad Pro. The training required for faculty to use it is almost nil. There’s a knob next to it that switches whether the computer or Visualizer is being projected, and everyone already knows how to use a pen. Wendy Carlin really likes having the physical pieces of paper at her fingertips when she teaches–It’s very easy for her to spread them out in front of her or flip pages to find just what she needs. The hardware looks pretty robust, and UCL bolts their Visualizers to the classroom desks. It would be a lot harder to lock down an iPad and Apple Pencil.

On the other hand, a 32GB 9.7” iPad Pro and Pencil costs $700 compared to about $3,000 for an entry-level desktop Visualizer. You could hand out iPads to the faculty who want to use them and let them bring them to and from the classroom. A realistic financial comparison is a little messy since there are a lot more faculty than classrooms at any particular university, and total cost would depend on the actual adoption/usage rate. The learning curve for the iPad is real, but I also think with a little practice, anyone can get pretty quick navigating a PowerPoint presentation during class. I think the biggest advantage of the iPad solution is its potential: Cool new apps come out and existing software gets new features almost every day.

The bottom line is that the Visualizer and the iPad Pro share big advantages over other more common technologies used for lecturing like PowerPoint on a computer or a whiteboard. They are a lot more similar than they are different. A world where we can physically write on our slides, do complex calculations by hand, and at the same time integrate this with existing content and have it easily viewable by everyone inside and outside the room is a pretty big leap forward.