Sunday, 21 August, 2005

Why mnemonics work for me

I was surprised to learn that some educated people discount the benefit of mnemonics.  "How can it be easier if it's more stuff to learn," is a common argument.  Invariably, these people don't quite grasp the intent of a mnemonic, which is to serve as a small key that unlocks the memory of the detailed information.

There's no doubt that memorizing the mnemonic and the information that it unlocks takes more space in the memory.  But that's not a problem--the human brain has way more storage capacity than anybody's ever used.  At least, it seems to.  The problem isn't storage space, but rather retrieval.  And often we "know" some piece of information, even know where it's stored.  We can retrieve it, but we can't decode it.  It's the "tip of the tongue" syndrome.

For example, everybody learns the names of the five Great Lakes in elementary school geography.  But for the life of me I couldn't reliably recite all of their names.  That is, until I remembered the word "HOMES" and attached it to the Great Lakes file in my head.  Now, if somebody asks me the names of the Great Lakes, I remember HOMES and can recite:  Huron, Ontario, Michigan, Erie, Superior.  The same happens if I have to remember the colors of the rainbow:  Roy G Biv becomes red, orange, yellow, etc.

Other mnemonics aren't quite as easy, and doubters just don't understand how I can say that "Do Green Snails Have Slippery Backs, Doc" is easier to remember than the names of Snow White's Seven Dwarfs.  I remember the names of the dwarfs, but I can't reliably recall them without first picturing those green snails and thinking "Do, Dopey.  Green, Grumpy.  Snails, Sneezy.  Have, Happy.  Slippery, Sleepy.  Backs, Bashful.  Doc."  Another good one is "Kings Play Chess On Fine Green Silk" to remind me of plant and animal classification order:  Kingdom, Phylum, Class, Order, Family, Genus, Species.

With sufficient usage, the mnemonic becomes unnecessary.  For example, I ended up using ITU phonetics often enough in military school, as a pilot, and in ham radio that I no longer have to rely on that goofy mnemonic rhyme that my friends and I made up more than 30 years ago.  I can just rattle them off.  But I don't have to recite the names of the Seven Dwarfs often enough to dispense with the green snails.

The reason the green snails and the green silk work for me is because they paint an image in my head.  When asked for the names of the dwarfs I can "see" somebody asking a doctor if green snails have slippery backs.  The dwarfs' names by themselves just don't paint that picture.  Granted, it's more to remember.  But storage is virtually unlimited.  Might as well use the space for a more efficient indexing scheme.