Subject: Memory – The Magic Number Seven
Event: George Miller’s paper “The Magic Number Seven, Plus or Minus Two: Some Limits on Our Capacity for Processing Information” is published, 1955
And finally, what about the magical number seven? What about the seven wonders of the world, the seven seas, the seven deadly sins, the seven daughters of Atlas in the Pleiades, the seven ages of man, the seven levels of hell, the seven primary colors, the seven notes of the musical scale, and the seven days of the week? What about the seven-point rating scale, the seven categories for absolute judgment, the seven objects in the span of attention, and the seven digits in the span of immediate memory? For the present I propose to withhold judgment. Perhaps there is something deep and profound behind all these sevens, something just calling out for us to discover it. But I suspect that it is only a pernicious, Pythagorean coincidence. -George Miller (1)
Have you ever wondered why phone numbers have hyphens? What is the difference between 206-333-2435 and 2063332435? The answer relates to the capacity we have to store short-term memories. In a landmark study published on this day in 1955, psychologist George Miller (1920-2012) determined that when it comes to short-term memory capacity, seven is the magic number. The magic of the hyphen in a telephone number, therefore, is that it allows us the “chunk” numbers together in groups in order to expand our capacity to remember them.
Miller’s work with memory built on the pioneering research of Herbert Ebbinghaus, who established what we know today as the forgetting curve (See THINKER’S ALMANAC – January 19). Like water in a glass, our memories evaporate quickly if we don’t make some effort to keep them. Ebbinghaus used himself as a subject, memorizing hundreds of three-letter nonsense words. Doing this, he established the keys to hacking our memories: spaced repetition and retrieval practice. If you want a memory to move from short-term to long-term memory and stay there, you must practice recalling it numerous times over a long period of time, including recall before and after periods of sleep.
Miller’s work dealt primarily with the capacity of our working (short-term) memories. Although our working memories have limits, we can extend these limits by chunking the information and organizing it into recognizable patterns.
For example, imagine you were trying to remember the following string of 13 letters: SRIASANAICIBF. Normally your working memory would be exhausted at about seven letters, but you might extend this capacity by organizing the letters into recognizable chunks: FBI-CIA-NASA-IRS. Now instead of 13 separate items, we have just four recognizable and easy to remember items.
More than just a strategy for remembering letters or numbers, chunking is a strategy for organizing ideas and information. When taking in a lot of information, look for ways that you might chunk it into different categories. Not only does this make the information easier to remember it also helps us engage our imaginations as well as our memories to creatively interact with what we’re learning. Likewise, if you are presenting information, consider your audience’s ability to take in information, and try to chunk it in a way that logically makes sense.
Recall, Retrieve, Recite, Ruminate, Reflect, Reason: How does the concept of chunking help you as a learner and as a presenter/teacher?
Challenge – Chunk the Muses: It was the Greek playwright Aeschylus who said that “Memory is the mother of all wisdom.” In Greek mythology, Mnemosyne, the goddess of memory, was the mother of the nine Muses who inspired human creativity. Do a bit of research on the Muses, and try to memorize the names and providence of each one. Also, try to employ some chunking to make your task more manageable.
1-“The Magical Number Seven, Plus or Minus Two: Some Limits on Our Capacity for Processing InformationOffsite Link,” Psychological Review, Vol. 63, No. 2, 81-97.
2-“George Miller Publishes ‘The Magical Number Seven, Plus or Minus Two. . . ‘“ History of Information.com
Tags: Herbert Ebbinghaus, retrieval practice, spaced repetition, forgetting curve, George Miller, chunking, Memory, Muses, Mnemosyne