Capacity of Short-term Memory
Whatever the cause or causes of forgetting over the short-term may be, there is consensus that it severely limits the amount of new information that we can retain over brief periods of time. This limit is referred to as the finite capacity of short-term memory. The capacity of short-term memory is often called memory span, in reference to a common procedure of measuring it. In a memory span test, the experimenter presents lists of items (e.g. digits or words) of increasing length. An individual's span is determined as the longest list length that he or she can recall correctly in the given order on at least half of all trials.
In an early and highly influential article, The Magical Number Seven, Plus or Minus Two, the psychologist George Miller suggested that human short-term memory has a forward memory span of approximately seven items plus or minus two and that that was well known at the time (it seems to go back to the 19th-century researcher Wundt). More recent research has shown that this "magical number seven" is roughly accurate for college students recalling lists of digits, but memory span varies widely with populations tested and with material used. For example, the ability to recall words in order depends on a number of characteristics of these words: fewer words can be recalled when the words have longer spoken duration; this is known as the word-length effect, or when their speech sounds are similar to each other; this is called the phonological similarity effect. More words can be recalled when the words are highly familiar or occur frequently in the language. Recall performance is also better when all of the words in a list are taken from a single semantic category (such as games) than when the words are taken from same categories. According to the available evidence, the best overall estimate of short-term memory is about four pieces or "chunks" of information. In free recall it has been shown, to the contrary, that there is no such "quantized" limit, rather it is a function of memory decaying with time.
Read more about this topic: Short-term Memory
Famous quotes containing the words capacity of, capacity, short-term and/or memory:
“It is part of the educator’s responsibility to see equally to two things: First, that the problem grows out of the conditions of the experience being had in the present, and that it is within the range of the capacity of students; and, secondly, that it is such that it arouses in the learner an active quest for information and for production of new ideas. The new facts and new ideas thus obtained become the ground for further experiences in which new problems are presented.”
—John Dewey (1859–1952)
“Rice and peas fit into that category of dishes where two ordinary foods, combined together, ignite a pleasure far beyond the capacity of either of its parts alone. Like rhubarb and strawberries, apple pie and cheese, roast pork and sage, the two tastes and textures meld together into the sort of subtle transcendental oneness that we once fantasized would be our experience when we finally found the ideal mate.”
—John Thorne, U.S. cookbook writer. Simple Cooking, “Rice and Peas: A Preface with Recipes,” Viking Penguin (1987)
“I still believe that if your aim is to change the world, journalism is a more immediate short-term weapon.”
—Tom Stoppard (b. 1937)
“Beauclerc: You’ve got a good memory for one who drinks.
Eddie: Drinkin’ don’t bother my memory. If it did, I wouldn’t drink. I couldn’t. You see, I’d forget how good it was. Then where’d I be? I’d start drinkin’ water again.”
—Jules Furthman (1888–1960)