LW - Spaced repetition for teaching two-year olds how to read (Interview) by Chipmonk

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Welcome to The Nonlinear Library, where we use Text-to-Speech software to convert the best writing from the Rationalist and EA communities into audio. This is: Spaced repetition for teaching two-year olds how to read (Interview), published by Chipmonk on November 27, 2023 on LessWrong.
Update: this post now has another video.
This father has been using spaced repetition (Anki) to teach his children how to read several years earlier than average.
Michael Nielsen and Gwern[1] tweeted about the interesting case of a reddit user, u/caffeine314 (henceforth dubbed "CoffeePie"), who has been using spaced repetition with his daughter from a very young age.
CoffeePie started using Anki with his daughter when she turned 2, and he continued using Anki with his son starting when he was 1 year 9 months. Here's his daughter's progress as recounted in January 2020:
My daughter is now about to turn 5 in a few days… She's still going strong -- she uses Anki every single day for English, Hebrew, and Spanish. She's very confident about reading, and moreover, she reads with ... "context". Many kids her age read mechanically, but she reads like a real storyteller, and that comes from her confidence. At the beginning of the school year her teachers said she definitely has the reading ability of fifth grade, and if we're just going by the ability to read and not focus on comprehension of abstract ideas, her reading level may rival an 8th grader.
(From Update on my daughter and Anki)
For reference, fifth graders are usually 10 or 11yo in the US, and 8th graders are usually 13 or 14yo, so this puts her ~5-9 years ahead of the average child.
You can see a video of his daughter reading at 2 years, 2 months later in this post.
CoffeePie has made several posts about their experience but I still had questions so I reached out to interview him back in January.
Interview
Responses have been edited for clarity.
What did you learn in going from using Anki on your daughter to your son? How has it gone with your son?
It's a hard question, because I got so much right. We were so wildly successful that I "cloned" just about every aspect with my son.
A couple of things I can think of:
With my daughter, I held back on lowercase letters for a long time because I thought it would confuse her, but when I started to introduce lowercase to her, to my extreme shock, she already knew them, down cold!
I think what happened is that she learned them just by looking at books, TV, magazines, storefront signs, menus, etc.
So when we started with my son, I started doing lower case letters the very day after we finished capital letters.
Another difference is that we did numbers the very next day after lowercase letters.
I really, really thought I was pushing too hard; I had no desire to be a "tiger dad", but he took it with extreme grace. I was ready to stop at any moment, but he was fine.
Another difference is that our expectations of what the kids were getting out of it had changed, as well. At first, I just really wanted my daughter to get a jump start on reading, but stupid me, I didn't realize there were unintended consequences. A four year old with a 3rd grade reading ability learns about a WHOLE lot more -- it opened up politics for her. She would read our junk mail, and learn who our council member was, who our representative is, the mayor, current events, history, etc. I know it's stupid of me to say, but I underestimated the effect that reading early would have on her breadth of learning.
One last thing is math. I mentioned that we started numbers early with my son. But we also started arithmetic. He wasn't reading by 3 the way Hannah was, but he knew all his multiplication tables up to 12 by 12. This year we tackled prime factorization, Fibonacci sequences, decimal and place values, mixed, proper, and improper fractions, light algebra, etc. I was much more aggressive with the math, and again, he handled it with grace. I was ready to stop at any moment.
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