Do Leeches downgrade SM efficiency?
Nattan (aka LittleFish) comments got me thinking and got me into search mode. Hope my whole brain had a search while you type mechanism; ok, maybe this is just to geeky.
Well, if you are current user of SM, or been trying to get help from the SM site, you now is not exactly easy to find a clear answer. Even if we do find the answer, could this be the only answer. This is one of the primary reasons why this blog got started, searching from SM true lovers. Those who want to go a step further in their SuperMemoing process.
“If you have many “wrong” answers on the same item, does this affect the overall algorithm in a bad way?” (LittleFish Comment)
So, does repeatedly answering bad (leaches), affect the SM algorithm making it less efficient?
At least 5 webpages on the SM site give clues to this question, although it repeats the same text and not surprisingly is an answer to another question. Because Nattan says he’ll experiment doing a separate set for leaches and I think that’s a good idea. I’ll try to analyze SM site response.
(David Mckenzie, New Zealand, Apr 8, 1998)
Is there any point in keeping collections separate?
No. Once you master categories, templates, and subset operations, there is no point. You gain global search, global registries, global repetitions, global optimization, etc. Presently, the item difficulty measure (A-Factor, or absolute difficulty factor) is absolute and does not depend on the context in which an item is placed. Only the length of the first interval will significantly be affected by the average difficulty of items in the collection. However, this shall not bear dramatically on the speed of learning. Especially that variable forgetting index for individual items makes it possible to set different first intervals for whole contents categories or branches of the knowledge tree (http://www.supermemo.com/help/fi.htm)
This answer does not conform to the simplicity principle, specially in the answer side of the item. Lets decompose the answer:
“No. Once you master categories, templates, and subset operations, there is no point.” (SM site)
What about before your mastered? (if you ever really do). Personally I think that if you are just starting, a good measure would be to make separate collections. For how long? well, it depends on your proficiency with SuperMemo, but maybe not two long (3 months or so). After your collection grows big, you’ll want to use just one collectioin. (Except for testing purposes: themes, layouts, organizing, even data).
“Presently, the item difficulty measure (A-Factor, or absolute difficulty factor) is absolute and does not depend on the context in which an item is placed. Only the length of the first interval will significantly be affected by the average difficulty of items in the collection.” (SM site)
Presently? well, not other information says nothing different, so this affirmation should still be true. The second part, about first interval length significantly affected, shows that indeed it is affected, as me and other found out. For those of us who don’t want this to happen using a second collection until the elements on it or a branch on it has no further leaches would be a good alternative.
Finally, I do think leaches affect us all, either in a bad or good way, last post on unconscious memorization wanted to help us all acknowledge that no matter how many times we have to repeat something it would finally stick.
But perhaps for many perfectionist, who don’t want to trust the haphazard construction of our mind, this is not enough. Those would like to give a try at Nattan’s recomendation of using two separate collections.