Pre-known items in a collection
Subject: Pre-known items in a collection
Items I add to my SuperMemo collection belong to one of two kinds: either items that are completely new to me (which, at first, I will forget in 2-3 days without review) or items that I already know well (which I will remember even after several months without review).
It seems like the well-known items (which are currently the bulk of my collection) skew the estimated forgetting curve in such a way that every new item gets an extremely long first interval (over a month).
When I see those new items again a month later and obviously fail, the next interval is just one day, which enables the learning process to proceed correctly. But, it means that an entire month was wasted during which I could have reviewed these new items and cemented them in my memory...
Is there any way to mark already-well-known items in a collection, even though they were just added and SuperMemo knows nothing about their real repetition history, so that they won't skew the forgetting curve? Or is there some other algorithmic issue at work here?
Here's a way to easily reproduce this issue:
First, create a clean new collection without changing any of the default settings (FI = 10%).
Then, create 3 new items and learn them.
Then, close SuperMemo and move your system clock a whole month forward. Note that it has to be a month - when I tried it with two weeks, the problem didn't reproduce.
Open SuperMemo again and learn your 3 items, marking all of them as "good".
Now, press F7 and click on Compute. You will see a metric of 0.0%.
Now, create a new item. As you can see, the new item's interval is 33 days!
it probably does not matter how long the interval is. If you score perfectly SuperMemo should assign longest interval possible. 33 is probably maximum allowable. Otherwise, infinity would fit perfection just right.
if you perform very well and get long intervals you can shorten them for harder items with Ctrl+Shift+R. If those items perform poorly at shorter intervals, you may reach some better balance.
for the first interval, all items go together. So you cannot separate them and produce separate forgetting curves even if you know some portions of the material are harder or easier.
After entering a new item, press CTRL-J to manually schedule the first review of the more difficult items for the next day. I suspect that after a short while of doing this and failing to recall some items after that 24-hour period, SM's estimates of your memory will start to level out and you will no longer need to do it.