This was a short project from winter quarter 2005 at UCSD. We interviewed and observed baristas at several coffee carts all over the UCSD campus. We discovered that there were significant problems with the way the grinder worked--it was hard to measure the right amount, and it kept getting stuck, making the barista stop everything else and dismantle the machine to clear it out.

However, the more interesting discovery was that the baristas did not like the espresso machines that were designed to be easier to use, with simple switches to control various features. They liked having a greater amount of control that the knobs on the more complex machines afforded. They all agreed that the other machines were easier to learn with, but when one is making hundreds of cups of coffee a day the learning period is not very long.

However, even the most skilled barista is more likely to make a mistake with one of the more complex machines, and indeed our most skilled interviewee did. We believe that part of the reason people may prefer these machines is not control but professional pride--a trained monkey can push a button over and over again to make coffee, but it takes a highly skilled barista to know when the milk is done by sound or where to turn the dial to heat the wand.

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