I’m going to lay out a bit of my reasoning for targeting low retention, but I’m not here to argue memory science and I don’t want contributors to the thread to be led off track. The thread is for experiences with this approach, and thoughts on how to make it work best.
Caveat out of the way, a few basic reasons one may want to do this: The evidence for the popular idea of a forgetting curve that resets with each successful recall is basically absent from the literature. There’s also no consistent evidence in favor of any particular spacing method: progressive spaces, equal spaces, on average there’s no evidence it matters. However, it does seem true that the more effort is required for a recall, the greater the boost to long-term retention will be: and this is true even if a card is failed. It’s very evident from the research that just because one fails a recall, this is no indication that it’s being filed in long-term memory any less effectively. Likewise, at 70% retention, each successful recall takes more cognitive effort than each of the successful recalls does at 90% retention. This means the value of that recall for durability of the memory is even greater. Thus, this approach may be especially useful when having information available in immediate memory for a test in the short-term (say, a few weeks) is not one’s priority. Something like learning a language when you’re in no rush to get conversational but want to have maximum progress two or three years in. One can probably both get more bang for the buck in terms of each card’s value, and then multiply these savings by the reduction of time required on flash cards overall, by targeting low retention. The sooner we initiate recall across larger gaps, the sooner we’re beginning the process of building long-term memories—there’s actually just no reason to think we have to successfully juggle something in short-term memory (recall in the handful of days after first learning) before we begin the process of long-term consolidation. We may want learning steps and short to medium term recalls simply for motivation and safety rails: to be able to gauge our progress to some degree along the way, to make sure we’re paying attention and trying to recall and encode the information at all times. It may even be that the only reason to have some minimum target (as opposed to just reading books and attempting recall of every unfamiliar word at whatever frequency they happen to appear) is so that we remain motivated, during a session, to keep attempting recall on every card, so that pathways will get the largest boost even if the card is failed.
If you’re familiar with the research supporting the above — or simply want to see how much value you can get out of Anki while using it less — this thread is for ideas and experiences.
My first experience has been working through the Jōyō kanji. I started with 8 cards a day, targeting 90%. This meant some ~60 reviews per day. I decided to blast through the 1500 remaining by doing 75 a day in a second deck, and I aimed for 70% retention so I wouldn’t get swamped by reviews while doing so. This got me through a chunk of the list in 3 weeks that would have taken me around 6 months to get through otherwise, and a short time afterwards I felt very comfortable with the new information. When I saw how effective this was, I decided to lower the target retention in the primary deck to 70%. My reviews for that day dropped from 60 to 4, and after some time I still felt just as confident with the information. These experiences have me interested in aiming for even lower retention rates, spending even less time on Anki, and making sure that I really concentrate, work hard to retrieve, and strongly encode information in the time I do spend. In fact, I may go ahead and target 50% retention for a list of uncommon kanji, and see how strong my confidence with that list is some months down the line.