There’s a right way and a wrong way to use your phone’s autocorrect, says the person who invented it. Ken Kocienda, former Principal Engineer of iPhone Software for Apple and author of the new book Creative Selection: Inside Apple’s Design Process During the Golden Age of Steve Jobs, led the team creating the first software keyboard for the first release of iOS. And he says that it’s possible to get too aggressive with autocorrect.
Autocorrect has evolved since its first form, but it’s still mostly based on the same fundamental factors. When you type a word, your keyboard’s software asks these three questions:
What dictionary words, when typed “correctly,” would make similar tap patterns to the user’s? (Your taps make a “keyboard constellation,” which your phone compares to the ideal constellations for every dictionary word.)
Which of these words are more common, and how much more common? (Kocienda points to Zipf’s Law, which predicts proportional word frequency in any language.)
Which of these words show up in the user’s “dynamic dictionary”—their most frequently used words, or the names of their contacts, or words they’ve retyped even after autocorrect changed them?
For each word, the software has to choose how much to weigh these three factors to decide what you meant. To understand how difficult this choice is, and how much is at stake, remember how long it took to teach your phone the word “fuck.”
But this whole process works best if you don’t stop to fix every word. It’s much more efficient to type a whole sentence or message, then proofread at the end. That’s what the system was designed for, and what works best in Apple’s user testing.
And this will get even truer as autocorrect and predictive text become more sophisticated, says Kocienda. As keyboards examine longer passages, they can recognise more mistakes. For instance, he says, your phone might think you typed of, but realise several words later that you meant to type if. (It knows you didn’t mean “Of you like piña coladas, and getting caught in the rain…”) The more advanced autocorrect gets, the more it can fix things without you constantly watching it. So learn to trust autocorrect. (Or turn it off.)