The science of keyboard design

The Handbook of Human–Computer Interaction, edited by Martin Helander, Thomas Landauer and Prasad Prabhu, is a book published in 1997 that attempts to summarise research relevant to the design of interactive software and hardware. Its 62 chapters fill 1500 pages and provide advice on a multitude of topics, covering analysis, design and evaluation of interactive systems, as well as the psychological and ergonomic underpinnings of human–computer interaction. One of those chapters is titled Keys and Keyboards and was written by James Lewis, Kathleen Potosnak and Regis Magyar. It considers virtually every imaginable factor involved in designing keyboards, and, by drawing from experimental studies, provides recommendations for each of them. Ever since I read this chapter a couple of years ago, I've been meaning to summarise some of their conclusions and to consider them in the context of modern keyboard design. The recent string of keyboard-related links on Daring Fireball (e.g. here, here, here, here, here and here) moved me to finally sit down and do it, so here it is.

Surface computing, move over!

For a few weeks now, my two team-mates at work and I have been using a “horizontal” whiteboard, lying across the desk surface between us. I had been wanting to try this for a while, but it wasn’t possible because of our previous desk arrangement. Now that we have this large area of space between us and no partitions, this small whiteboard fits perfectly without getting in the way.

We’ve found ourselves using it virtually every day, illustrating explanations, walking through calculations and brainstorming design ideas. Visitors will intuitively pick up a pen and start using the whiteboard when explaining things. It somehow seems to invite people to use it more than most whiteboards. However, it’s not only a collaborative tool: it also makes a great scratch-pad when you’re brainstorming on your own. To ensure that it stays useful, we make an effort to keep the board clean; nothing tends to stay on there for longer than a day or so.

Overall, it’s being used far more than any wall-mounted whiteboards we’ve had near us, and I think this is due to two key differences to wall-mounted boards. Firstly, each one of us can reach the board very easily without having to get up. You just turn your chair slightly and there it is. Secondly, the whiteboard is between us, so it feels less like a presentation aid and more like a collaborative work surface, accessible equally well from all sides.

If your work involves collaborative problem-solving, and if your desk arrangement allows it, I highly recommend setting up a whiteboard like this. Don’t make it too big, because you won’t be able to reach all corners and it will also eat into your desk real-estate. I think ours is 90×60 cm, which is just right. I also recommend investing in some pens with a finer tip than the standard ones you tend to get. Those are designed to be visible from a few meters away, but you’ll find them too thick for handwriting at a comfortable size for close-up work. Edding do quite a range of dry-erase board markers.

The Non-Wheel iPod

Whenever you see the rumoured next-generation video iPod mentioned, the expected features always include a huge screen covering the front of the device and a “virtual”, touch-screen-based click wheel.

I may be missing something here, but what exactly would be the point of that? The reason the iPod has a scroll wheel is to make scrolling easier on a device that doesn’t allow more direct manipulation of screen content. If you had a touch screen, the grounds for having a scroll wheel would disappear, and you could just use a scroll bar, right? A scroll bar would allow scrolling directly to any point in a list and would involve less (and less awkward) physical movement.

Also, if you had such a nonsensical, virtual scroll wheel, you’d be waving your thumb around over the contents of the screen all the time, which doesn’t sound like a clever idea. Of course, you could dedicate a section of the screen for this wheel, but wouldn’t you rather use that space to make the list taller?

So I think either the creative minds behind the rumour sites didn’t think this one through properly, or the creative minds at Apple are making some rather silly decisions. Let’s hope it’s the former.

Mighty Mouse impressions

I have been using a Mighty Mouse for about a month now which I got as a leaving present from my kind colleagues, so I thought I'd share my impressions. I intentionally waited for a few weeks to allow myself time to get used to it.

Up to now, my mouse of choice has been a Microsoft Wheel Mouse Optical, a two-button mouse (three if you count the scroll wheel). I really like the shape, the feel of the buttons, and its durability.

One of my first thoughts when I started using the Mighty Mouse was that the button was too hard to press. I searched for a switch to adjust the firmness, as I had seen on the Apple Bluetooth Mouse, but no luck. I got used to it eventually, but initially this caused my hand to get tired quite easily. It's a shame they don't have the adjustment feature across all their mice. I can't see any obvious reason for not including it.

Another reason why my hand and wrist felt tired was that I was used to resting my hand on my Microsoft mouse, which is quite high at its highest point. The Mighty Mouse is much flatter. Also, I think because the whole surface forms the button, I felt hesitant to put too much weight on it.

What people probably wonder about most is how well right-clicking works. At least I did. As you may have read elsewhere, it requires you to actually lift your index finger off the surface. As long as your finger touches the area to the left of the scroll ball (for the right-handed setting), any clicks are registered as primary clicks. I wasn't sure if this would be a problem, because I didn't actually know whether or not I usually lifted my index finger. Well, it turns out I didn't. On other mice, I was just applying more pressure on the right side. I wouldn't say that getting used to Apple's prescribed technique was hard, but it did take some conscious effort at first. I still fail very occasionally, even after four weeks of using it.

The side buttons are also interesting. You squeeze them to activate them, but although they give slightly, there's no tangible click. Instead, you get feedback in the form of a clicking sound from the built-in speaker. This sounds very natural and I find it actually gives you the illusion of feeling the click as well. It's only when the mouse is disconnected and has no power that you're sure there's no physical click. Of course, this whole concept breaks down if you are in a noisy environment or if you are deaf. Also, the buttons really give only slightly, so I tend to apply quite a lot of pressure, which is tiring.

I have to say I don't really use the side buttons. The main reason is their positioning. When I hold the mouse in a natural position, my ring finger is on the side button on the right, but my thumb is just behind the left one. So to get a grip, I either need to move forward my thumb (and therefore my wrist) or hold the mouse slightly angled to the left. This is kind of crappy, since it seems like an obvious problem and shouldn't be hard to fix (just make the buttons wider, spanning further back).

On to the Mighty Mouse's other big curiosity: the scroll ball. Let's look at traditional, vertical scrolling for now. In a nutshell, it feels great. Scrolling is much smoother than on other mice, because it seems to have a higher resolution. Scrolling produces soft clicking sounds, which are artificial like on the side buttons, but here the illusion of tactile feedback is even more convincing. Also, you have to apply a tiny bit of pressure while using it, so if you touch it very lightly and move it, nothing happens. I guess the reason for this behaviour is to avoid accidental scrolling when you brush over the ball while moving your fingers. Apple did an amazing job of tuning the threshold for this so you probably will never notice.

What I was looking forward to most in this mouse is the idea of being able to scroll horizontally without having to hold the Shift key. Unfortunately, the result here has been disappointing. It works, but it doesn't work very well. The problem is one of ergonomics. To scroll vertically, you can use about an inch of your index finger's length to move the ball, from the tip of the finger to just behind the first joint. This not only gives you a fairly good range, but also very fine control. In contrast, when scrolling horizontally, only a very narrow part of you finger can make contact with the ball, so you have to keep scrubbing to scroll longer distances. That could be fixed by accelerating horizontal movement more than vertical, but the other problem is that horizontal scrolling is very hard to control. This is partly due to the limited range, of course, but also because your finger sticks to the shiny surface of the mouse on either side of the scroll ball. When you apply more force to overcome that stickiness, your finger suddenly sweeps across the ball much faster than you intended, resulting in very jerky movements. It can be quite frustrating.

I can think of two possible improvements. One is to make the surface rougher, at least around the scroll ball. The other is to expose a bit more of the sides of the scroll ball, by making the surface of the mouse slightly concave at the top.

The other thing you can do with the scroll ball is click. The thing to note here is that it's not the depressing of the scroll ball which causes the click, but pressing the whole mouse down while your finger is on the scroll ball. In fact, the same pressure detection used to activate the scroll ball when scrolling also seems to give the condition for a middle click. This means that a middle click doesn't actually feel any different from a normal click, which can be a bit confusing. But at least you don't have to lift up your other fingers in order for it to work.

So the Mighty Mouse delivers many novel ideas, but how well these work is quite a mixed bag. Vertical scrolling is the only real winner. Once you're used to this one, traditional scroll wheels will feel clunky and primitive. Although some of the other features, like horizontal scrolling, are potentially useful, others feel like they're just there to make the mouse as unconventional as possible.

Innovation is appreciated, but not just for the sake of innovating.