Wednesday, March 17, 2010

THE MAGIC NUMBER 7

At a talk by an innovation expert, I learned a surprising bit of information about writing lists, ads, and other informative copy. Put 7 objects on a table, then ask someone to tell you how many things are there. You will probably get the answer "7" immediately. Try it again with a new person and 8 objects. Instead of getting the immediate answer "8," most people will count "1, 2, 3... " before deciding. This has been tested, and an immediate answer usually comes at 7 plus or minus 2. To start counting when seeing 5 objects shows limited ability in this area. To recognize up to 9 without counting shows a special talent. That means the best list for anyone to grasp quickly is not a "Top 10," but a "Top 7" list. That amount of information sticks the best. Watch for our Top Seven lists in the future.

8 comments:

Ann said...

That is fascinating! Have to try it out at the next family gathering. Someone tell David Letterman.

Anonymous said...

I learnt that to take in a number of objects at one glance you only get to 4. Try with a bunch of matches and see when you have to start coun ting to make sure.
christian

Anonymous said...

I believe this is why telephone numbers started out as 7 digits.

Lawrence said...

Not new. This concept has been kicking around since 1965, It's origin was cognitive psychologist George Miller's article described in Wikipedia:

"The Magical Number Seven, Plus or Minus Two: Some Limits on Our Capacity for Processing Information" (Miller 1956) is one of the most highly cited papers in psychology.[1][2][3] It was published in 1956 by the cognitive psychologist George A. Miller of Princeton University's Department of Psychology in Psychological Review. It argues, in essence, that the number of objects an average human can hold in working memory is 7 ± 2; this is frequently referred to as Miller's Law.
In his article, Miller discussed a coincidence between the limits of one-dimensional absolute judgment and the limits of short-term memory. In a one-dimensional absolute-judgment task, a person is presented with a number of stimuli that vary on one dimension (e.g., 10 different tones varying only in pitch) and responds to each stimulus with a corresponding response (learned before). Performance is nearly perfect up to 5 or 6 different stimuli but declines as the number of different stimuli is increased. The task can be described as one of information transmission: The input consists of one out of n possible stimuli, and the output consists of one out of n responses. The information contained in the input can be determined by the number of binary decisions that need to be made to arrive at the selected stimulus, and the same holds for the response. Therefore, people's maximum performance on one-dimensional absolute judgement can be characterized as an information channel capacity with approximately 2 to 3 bits of information, which corresponds to the ability to distinguish between 4 and 8 alternatives.

Nostalgia Antiques said...

As I understand it, we can most easily remember series of up to 7 numbers, which is why telephone numbers contain 7 digits.

Anonymous said...

I've heard this before...I believe that's part of the reason why phone numbers are seven digits (without the area code).

Diane said...

Thank you for explaining this phenemenon. I always feel stupid for having trouble quickly counting out my multiple sets of 7 pills each week when filling my pill reminder. After researching your information further, I found that this skill is called "subitizing" and people who have a problem subitizing may have "Balint's syndrome". Fascinating!

Anonymous said...

So THAT is why people keep forgetting the Ten Commandments!
:-)