Gideon Lewis-Kraus has a Wired article that works a little too hard to be relentlessly amusing but tells an interesting story about how autocorrect came to be and how it works:
The notion of autocorrect was born when Hachamovitch began thinking about a functionality that already existed in Word. Thanks to Charles Simonyi, the longtime Microsoft executive widely recognized as the father of graphical word processing, Word had a “glossary” that could be used as a sort of auto-expander. You could set up a string of words—like insert logo—which, when typed and followed by a press of the F3 button, would get replaced by a JPEG of your company’s logo. Hachamovitch realized that this glossary could be used far more aggressively to correct common mistakes. He drew up a little code that would allow you to press the left arrow and F3 at any time and immediately replace teh with the. His aha moment came when he realized that, because English words are space-delimited, the space bar itself could trigger the replacement, to make correction … automatic! Hachamovitch drew up a list of common errors, and over the next years he and his team went on to solve many of the thorniest. Seperate would automatically change to separate. Accidental cap locks would adjust immediately (making dEAR grEG into Dear Greg). One Microsoft manager dubbed them the Department of Stupid PC Tricks. [...]
With these sorts of master lists in place—the corrections, the exceptions, and the to-be-primly-ignored—the joists of autocorrect, then still a subdomain of spell-check, were in place for the early releases of Word. Microsoft’s dominance at the time ensured that autocorrect became globally ubiquitous, along with some of its idiosyncrasies. By the early 2000s, European bureaucrats would begin to notice what came to be called the Cupertino effect, whereby the word cooperation (bizarrely included only in hyphenated form in the standard Word dictionary) would be marked wrong, with a suggested change to Cupertino. There are thus many instances where one parliamentary back-bencher or another longs for increased Cupertino between nations. Since then, linguists have adopted the word cupertino as a term of art for such trapdoors that have been assimilated into the language.
In the two decades since Hachamovitch moved from the manual coding of corrections like judgement to his loftier executive role in the ambit of data science, autocorrect has followed suit. Autocorrection is no longer an overqualified intern drawing up lists of directives; it’s now a vast statistical affair in which petabytes of public words are examined to decide when a usage is popular enough to become a probabilistically savvy replacement. The work of the autocorrect team has been made algorithmic and outsourced to the cloud.
I was temporarily derailed by “He clearly takes a marmish pride in the artifacts,” having never seen the word marmish and not finding it in my dictionaries; Urban Dictionary says “Conservative to the point of being boring, dull or ugly; usually referring to a manner of dress and/or personality,” which doesn’t really make sense here, but I get the general idea. What really took me aback was “As someone who typed the entire first draft of his book on a phone…” Seriously? The twenty-first century is a weird place for those of us who didn’t grow up in it.