the joy of boolean logic

May 5, 2007
Programming Geekery of the Moment
Today in a UI design meeting one of the consultants mentioned that users "mix up AND and OR" when setting up computer queries.

It took me a moment to get beyond the "sheesh, users!" mindset and start to look at it from their point of view. I think I got it though...

Say you were looking to buy a used car, using some kind of database. And that you wanted a fast car, or at least one that was painted red, so that it looked fast. In computer terms you might set up a database query, something like "SHOW ME CARS WHERE CAR IS FAST OR CAR IS RED". That would give you a list of all the fast cars, and all the red cars, and of course all the cars that were both fast and red. ("SHOW ME CARS WHERE CAR IS FAST AND CAR IS RED" would return only cars that were both fast and red.)

But non-technical users might think of the question differently. They might think of the question as "Show me all fast cars, and show me all the red cars"... I mean, you want to see both sets of cars, right? So there's kind of ambiguity there, depending on how the user interface prompts the user to ask their question.

(Of course, when writing a query builder it gets uglier than that... I mean going back to the first query, what you really want to ask is "SHOW ME CARS WHERE CAR IS USED AND (CAR IS FAST OR CAR IS RED)"... it's a challenge to make queries like that easy for users to enter.)

Vocabulary of the Moment
When I accidentally ran across this word in the dictionary one day, it was instantly familiar, before I even got to the definition.
I didn't need to know phonetics to recognize the approximant liquid of that "or," the plosive "ga," the fricative "z," or the labial, nasal, sigh of the final "um."
--Alison Bechdel describing a vocabulary discovery in her touching autobiographical graphic novel "Fun Home". I never realized what a visceral word it is!

Backlink of the Moment
Heh, speaking of cars... Don't hear much from therosser these days, but he LJ'd about how he bought his new Honda Fit site unseen, and it was a kisrael post that first brought it to his attention. That's weirdly flattering!

In my comments on his post I mention how I'm not so crazy about Scion's "replacement" for my xA... and their redesigned xB seems to lose the fun of driving a box.

I know I'm older than their target demographic anyway, but I think I've lost whatever brand loyalty I've had to Scion...