Pang: Who wrote the documentation? Most people are familiar with user documentation, but what is necessary to write down to make it possible to manufacture millions of something you design?
Sachs: Back then, I don't think we knew what documentation was. [Pang laughs] Documentation was the amount of information required so you could get 50 made, and from then on it was somebody else's problem. But then, the mouse was the first real industrial production product I'd ever worked on.
In mechanical engineering, the documentation really is an adequate set of documented drawings, and a parts list. Beyond that, there was so much intangible intellectual property about how something works that it was really transferred verbally, or through team meetings about what was important. So a design team would sit down with a manufacturer and transfer their knowledge in an interpersonal communication rather than a technical specification, because so much could be lost if you simply said, for example, "This needs to be lubricated with lubricant X," instead of having them understand that that lubricant X is so critical that if you contaminate any other part of the system with it it'll fail after a year. We wanted to transfer more than just the basic information. So it was really a human-to-human team knowledge transfer. From there, Apple took care of documenting it for their own manufacturing purposes and their own archives.
But often what is lost in that kind of historical documentation of a product is the Zen of the product, because it's something you can't write down. You could write down that a switch should have a certain activating force, and a certain sound-- though a sound is hard to document without sampling it. Certainly it's almost impossible to document the feel of something. And so you describe it. And to this day, in 1999 and 2000, that's true. At SoftBook, we have a product that has a switch-- the page switch of an electronic book-- and when it comes to final approval, they actually give it to me, and I feel it and say if it has the right feeling or not. Because somehow or another, it's my brain, and my tactile senses that's calibrated to know what feels right. And then when we make enough of them, other people can feel it, and they get accustomed to it, and they too can pass on the right feel. But ten years from now, if there's a lack of continuity, the feel of something is not something we have the ability to document. You would have to go back and refer to an actual sample to refer to-- and possible other samples, so you can see that this one is too stiff, and this one is too soft, and this one is too loose-- so people can get an understanding of why this one is the way it is.
That's the Zen of the product, which fortunately we have the ability of transferring personally from one person to another. For a practical point, the way we do this in mass-production is, a designer goes to the factory, and is there on the assembly line seeing to it that the Zen of the product-- in addition to the technical specs-- are there. Because there are some things you simply can't document, or things where language fails us. The only solution we have found to almost guarantee satisfaction is to have a human go to the location, actually use all of their senses to determine-- along with the written documentation-- that it is what it's supposed to be.
One example of the Zen of mousing has to do with the tightness of the interaction between the mouse's actions and the computer's response. There was always a big difference in this between the Macintosh and the PC, for those of us accustomed to the Mac. The Macintosh was designed with the mouse as part of the system, and there was a very, very tight interaction: both a precision of motion-- of moving the pointer around on the screen-- and a feeling that you had total control of where that pointer was, and its speed and position. With the PC, because the mouse was an add-on, there was almost a rubber band-like connection between your hand and the mouse: either the mouse would lag behind, or it would stutter, or you would have trouble making a precision alignment. That interaction has always, maybe until quite recently, a distinct advantage of the Mac over the PC. The mouse was such an integral part of the design from the beginning that the precise control became apparent when you moved away to a PC.
I have a theory that one never notices how fast a computer is, you only notice how slow a computer is. A similar thing holds true for the mouse: you don't notice how tight the interaction is until you go to another machine, where there's a very loose interaction, which becomes quite annoying. So as computer technology has changed, the interface between the mouse and the computer has improved consistently to provide that superb connectivity between the hand-eye coordination, and what goes on on the screen. You see this with the USB mice of today, where the mouse has to be given a very high priority: when you move it, the cursor or arrow has got to move regardless of what else the computer is doing because it's a very disturbing thing to have a delay. It's like an echo on a telephone-- you just can't ignore it.
As a result of that, we always felt that people who used early PCs didn't know what they were missing. I found the early PCs unusable, either because the mouse itself was designed as an awkward block with three buttons, or because the interaction with the machine was lame. And yet hundreds of thousands, if not millions of people, were told that this is the way a computer is supposed to work. For a while I thought that it might kill the mouse, because people wouldn't like it. But people were resilient and patient, and computers improved over time, so that now, I believe, all computers have a fine interaction between-- in this very subtle manner-- between what your eye and hand do, and what system actually does.