Siri Response Times

I was listening to the latest episode of Accidental Tech Podcast, and they had a segment about Apple’s seemingly institutional inability to get online services right. It made me think about this anecdote from Marissa Mayer back in 2006, as relayed by Greg Linden:

Marissa started with a story about a user test they did. They asked a group of Google searchers how many search results they wanted to see. Users asked for more, more than the ten results Google normally shows. More is more, they said.

So, Marissa ran an experiment where Google increased the number of search results to thirty. Traffic and revenue from Google searchers in the experimental group dropped by 20%. Ouch. Why? Why, when users had asked for this, did they seem to hate it?

After a bit of looking, Marissa explained that they found an uncontrolled variable. The page with 10 results took .4 seconds to generate. The page with 30 results took .9 seconds.

Half a second delay caused a 20% drop in traffic. Half a second delay killed user satisfaction.

If a half second difference made people search less on Google, imagine how much less people are using Siri given that its response times are often multiple seconds long. I think the single biggest improvement Apple could (and really must) make to Siri is to make it faster. And that’s exactly the sort of thing Apple has never really shown the chops for.

★ Thursday, 17 October 2013