BYTE: The user-interface design seems to have been difficult.
Tesler: That was the hard thing that affected the most people. A lot of software and hardware engineering issues were very difficult, but they affected only a few people. Interface issues affected half the division because Training, Publications, Marketing, and the software person implementing the application all had an opinion. People like us who were overviewing all the applications had opinions, in-between managers had opinions, kibitzers on the side had opinions, too. Not everybody can talk about what gate to use in some circuit or what routine to use in some program, but everybody can talk about the user interface. So we had to accommodate all of these things. And it turned out that good ideas and good criticisms came from everywhere. We had to come up with some objective way to decide. Thatâ€™s why we established the methodology which involved user testing. We had a procedure for proposing changes, reviewing the changes, narrowing it down to a few choices, with certain criteria like consistency and parsimony. And then we actually implemented two or three of the various ways and tested them on users, and thatâ€™s how we made the decisions. Sometimes we found that everybody was wrong. We had a couple of real beauties where the users couldnâ€™t use any of the versions that were given to them and they would immediately say, â€œWhy donâ€™t you just do it this way?â€ and that was obviously the way to do it. So sometimes we got the ideas from our user tests, and as soon as we heard the idea we all thought, â€œWhy didnâ€™t we think of that?â€ Then we did it that way.
There is a really good point here that probably gets lost in most companies.
UI changes are very prone to 'opinions'. You know they saying, ask two people for their opinion and you get three. It seems that Apple has been able to, from the start, recognize the nature of opinions being conflicting, based on ideas that are not fully developed or thought through, or just flat out wrong. (yes I know many opinions have good ideas too!) Recognizing this allows them to approach opinions not as an end all be all, but it allows them to use an engineering/scientific method approach of testing and factually supporting ideas that come out of opinions.
Google is another company that I know goes through great efforts to factually measure changes (and potential changes), test user actions and reactions, and to prove or disprove causes. I'm sure it's not a coincidence that they also make amazingly high quality products.