Behind the Interview: Quoting Smart Friends

I don’t normally post links to when I’m quoted in the press (seems a little pretentious, even for me), yet it can be fun going behind the scenes of an interview sometimes. A quote on Google’s personalized search results in Direct Magazine is a great opportunity:

For another thing, optimizing for the possible variations in
personalized search is close to mathematically impossible. “I had a
friend at UC Berkeley calculate the possible permutations for a search
that could have 25 links—a totally arbitrary number– show up in the
ten slots on a Google results page,” Berkowitz says. “The total worked
out to about 11.9 trillion possibilities.”

This could have turned out completely differently. The reporter, if he wasn’t so kind, could have said, "If Berkowitz brushed up on his fifth grade math skills or knew how to use a scientific calculator, he’d have figured out on his own that this would be 11.9 trillion possibilities." But instead, he let me off the hook and made it sound like I have friends in high places. Indeed, Andrew Marcus, PhD candidate in Berkeley’s chemistry department (I’m sure I’m butchering the attribution somehow, so forgive me), was kind enough to check my math, as was colleague Andrew Chang.

For both Andrews, my question on permutations was the easiest math question they answered all year, but the Berkeley reference looked great in print. You can’t keep enough Andrews on your speed dial.