Pardon the copying below, but I just had to include this on the blog since I discovered this stuff this morning. After my post yesterday citing Miller, I thought it my duty. Edward Tufte has a long series of post and comments on the mis-reading and mis-use of George Miller’s article. Here are some excerpts from the exchanges. (The complete series is found here.)

The magical number seven, plus or minus two: Not relevant for design

Now and then the narrow bandwidth of lists presented on computer screens and bullet points on PowerPoint slides is said to be a virtue, a claim justified by loose reference to George Miller’s classic 1956 paper “The Magical Number Seven, Plus or Minus Two.” That essay reviews psychological experiments that discovered people had a hard time remembering more than about 7 unrelated pieces of really dull data all at once. These studies on memorizing nonsense then led some interface designers to conclude that only 7 items belong on a list or a slide, a conclusion which can be sustained only by not reading the paper. In fact Miller’s paper neither states nor implies rules for the amount of information to be shown in a presentation (except possibly for slides that consist of nonsense syllables that the audience must memorize and repeat back to a psychologist). Indeed, the deep point of Miller’s paper is to suggest strategies, such as placing information within a context, that extend the reach of memory beyond tiny clumps of data. George A. Miller, “The Magical Number Seven, Plus or Minus Two: Some Limits on Our Capacity for Processing Information,” Psychological Review, 63 (1956), 81-97 here.

At Williams College in September 2000, I saw George Miller give a presentation that used an optimal number of bullet points on an optimal number of slides–zero. Just a nice straightforward talk with a long narrative structure. (George and I were there to pick up honorary degrees during the dedication of a new science building at Williams College. In addition, Donald Knuth’s talk as well as my own deployed no bullet lists.)

– Edward Tufte, April 20, 2003

George Miller on the relevance of +/- seven
Here is a comment by the George Miller on the scope and relevance of his classic essay:
From: George Miller
To: Mark Halpern
Subject: Re: citation for your disclaimer

Many years ago landscape architects used my +/-7 paper as a basis to pass local laws restricting the number of items on a billboard. It was funded by the big motel chains; if you run a mom-and-pop motel you have to put a lot of information on your sign, but if you have a franchise everybody knows you have hot and cold running water, color televisions, free breakfasts, etc. The restriction on billboard content was driving the small motels out of business.

The same argument was used in the Lady Bird Johnson Act to prohibit billboards within X feet of highways, and the billboard industry (a strange group that deserves an essay of its own) was hurting. They hired a man to travel around from town to town trying to refute the claims that more than 7 items of information could cause accidents. The man’s wife did not like her husband being constantly on the road, so she asked him about it. He told her that the root of his trouble was some damn Harvard professor who wrote a paper about 7 bits of information. She, being herself a psychologist, said that she did not think that that was what Professor Miller’s paper said.

Armed with this insight, he looked me up and told me the whole story about my career, unknown to me, in the billboard industry. There was much more to it than I have outlined here, and I was shocked. So shocked that I wrote a long letter thing to set the record straight. The letter was published in the monthly journal of the billboard industry and that was the end of it. Unfortunately, I no longer have a copy of the letter an I don’t recall the name of the journal (this was all back in the early 70s) so I cannot quote to you its contents. But the point was that 7 was a limit for the discrimination of unidimensional stimuli (pitches, loudness, brightness, etc.) and also a limit for immediate recall, neither of which has anything to do with a person’s capacity to comprehend printed text.

If you want to quote the original article, it is on line and you can find a pointer to it at www.cogsci.princeton.edu/~wn. But if that is too time consuming - yes, you are right: nothing in my paper warrants asking Moses to discard any of the ten commandments.

Good luck, g.
(This is posted at http://members.shaw.ca/philip.sharman/myth.html )
– Edward Tufte, April 26, 2003

Halpern’s email leading to Miller’s reply
Dear Mr Tufte,
You have posted a letter from George Miller to me in which he replies to one from me. I think his letter would be better understood if you had printed mine along with it; as it is, you have an answer without the question that prompted it. His reference to Moses, for example, will probably not be understood without a prior reading of my letter to him. Yours, Mark Halpern

From: Mark Halpern Sent: Thursday, July 30, 1998 12:04 PM To: [George Miller, Princeton University] Subject: citation for your disclaimer

Dear Professor Miller,

The director of the technical writing group which I serve as editor has issued an edict that lists and procedures in our printed and screen-displayed documentation should not exceed seven, or maybe nine at the most, items. This is of course a silly rule, whatever its origin, but I think that its source in this case is a fading memory of a third-hand report of a bad reading of your classic 1956 paper.

Of course you are in no way responsible for the misreadings of your paper, and the silly things done in its name, but I hope you can help my organization, at least, climb back out of the pit it has dug for itself, using your paper as its shovel. I have seen somewhere a quotation from you, or a paraphrase of your words, in which you deplore the strange conclusions that some have drawn from your paper, and express your dismay over all the half-baked rules that people have promulgated, citing it as their authority.

In my attempt to get our director to rescind his bad rule, I would like to be able to quote your very words against him; would you tell me where I might find such words? Or, if what you’ve said in the past is not on record, could I induce you to say now that nothing in your paper should be taken as warrant for asking Moses to discard at least one, and preferably three, of the Commandments?

With my thanks, Mark Halpern

– Mark Halpern (email), November 3, 2007

I first was made aware of George Miller’s study in grad school for communications at West Virginia University in the 70s. Mike Burgoon, my professor, had us read it. He had been at Michigan where Miller was a professor.