[PRL] linguistics question

[Jeffrey D Palm]

There's a linguistics theory (I think) that states something such as:

Speakers are lazy and want to use as limited a vocublary as possible -- 
i.e. have multiple meanings for words.  But listeners would rather have 
as unabmiguous a vocabulary as possible -- one word, one meaning.

Does any know the name of this theory?  I'm pretty sure it has a name.

Thanks for any help.
Jeff
-- 
Jeffrey Palm --> http://www.ccs.neu.edu/home/jpalm