Short-Term Memory (STM) has a limited capacity of about seven items, and a limited duration of about 30 seconds. Because of its limited capacity, STM is the bottleneck in the memory system. If we can only hold about seven items at a time in STM, then there are limits on how much information we can transfer to Long-Term Memory.
In order for me to demonstrate I will give you a series of letters and ask you to study them for 30 seconds, then look away and write them down without looking back at the screen:
I W L L I E T B K W F C R O
Now, were you able to get them all? Chances are you couldn’t, because 14 is more than our short-term memory can handle at one time.
Now take the series of letters and break them down into three or four sections and study each section by itself. After you learned each section, or ‘chunk’, you can put them together and repeat the entire series.
What you just did is called “chunking,” and it is a much easier way to memorize a larger group in a series.
The term ‘chunking’ originated from a paper written by George A. Miller titled, “The Magical Number Seven, Plus or Minus Two: Some Limits on our Capacity for Processing Information.” Miller saw that the brain seemed to be able to process information easier if it was divided up into smaller groups. Simply put, “short-term memory has a capacity of about ‘seven plus-or-minus two’ chunks.” The brain is only capable of processing about 7 — 9 items at a time, and with monosyllabic English it can be as little as four or five. Numerous studies conducted since then to support this theory. He did acknowledge, however, “We are not very definite about what constitutes a chunk of information.”
Going by Miller’s theory it should be possible to increase our short-term memory by mentally breaking down the low-information content into smaller bits, or chunks. We should then be able to take these smaller chunks and add them to other small chunks to form high-information content (the whole context). For example: If you were trying to remember a speech you would break down the speech into smaller sections or paragraphs. By learning each section individually you can then combine them to have memorized the entire speech.
As a memory technique, chunking can be understood by the way we group numbers in our daily life. For example: If you want to remember a phone number you would break the number down into smaller groups – Area code (3 digits), Location (3 digits), and the number (4 digits). 555-555-5555 (3-3-4). Instead of remembering 10 digits at once we break it down into three groups. Three smaller groups are easier to remember than one long series.
Wikipedia — Chunking: http://en.wikipedia.org/wiki/Chunking_%28psychology%29
Memory Techniques — Chunking: http://daphne.palomar.edu/stat/mark/stm%20chunking.htm