For many years, linguists have tended to believe that the length of a word was associated with how often it was used, and that short words are used more frequently than long ones. This association was first proposed in the 1930s by the Harvard linguist George Zipf. Zipf believed that the relationship between word length and frequency of use stemmed from an impulse to minimize the time and effort needed for speaking and writing, as it means we use more short words than long ones. But Steven Piantadosi at the M.I.T. say that, to convey a given amount of information, it is more efficient to shorten the least informative—and therefore the most predictable—words, rather than the most frequent ones.