Так ведь?
Или давайте, как и в случае с «вареньем», прочтем оригинал? :)
Итак, в 1956-м году, за четыре года до рождения моего отца, дядюшка Джордж Миллер, красавчик на фото слева (биография, wiki), опубликовал в 101-м номере журнала «Психологический обзор» (wiki) статью за номером 2, 343-352, которая называлась «Магическое число семь, плюс или минус два. Некоторые ограничения наших способностей по обработке информации».Никаких своих опытов в этом исследовании Джордж не описывал, хотя русская вики пишет, что: «Джордж Миллер во время своей работы в Bell Laboratories провел ряд экспериментов, целью которых был анализ памяти операторов. В результате опытов он обнаружил, что...»
Джордж просто собрал и проанализировал множество исследований других учёных и дополнил их собственными выводами.
Хороший оригинал с нормально завёрстанными картинками можно прочесть на странице www.all-about-psychology.com/george-a-mi
Уродская ПДФка с картинками в конце называется «Miller GA Magical Seven Psych Review 1955.pdf», гуглите, если хотите.
В исследовании говорится про абсолютное суждение и про объем кратковременной памяти.
Абсолютное суждение
Если взять, например, небольшой кусок трубы (это я вам от себя объясняю, в оригинале этого нет :) и туда что-то начать говорить, то всё что в трубу «влетит», «вылетит» из неё без потерь. То есть зависимость влетело-вылетело будет линейная y=x.
Если же вместо трубы взять человека, то оказывается, что сначала количество вылетевшего будет так же равно влетевшему, но потом, с ростом влетающей информации, вылетающая начнёт уменьшаться (будет теряться где-то в голове) и будет асимптотически приближаться к некому N. Это N Джордж назвал ёмкостью канала передачи человека.
Речь при этом идет только об одномерных воздействиях (стимулах). То есть рассматривались случаи, когда количество информации увеличивалось строго в одном измерении.
Например, первое исследование, которое рассматривает Джордж, было проведено Ирвином Полаком в 1952 году. В исследовании испытуемых просили присвоить номера разным звукам, которые отличались между собой только по частоте. Когда звуков было два или три, испытуемые не путались. Когда звуков было пять путались частенько, а когда звуков было 14, ошибок было очень много.
Джордж собрал исследования, где воздействиями были: звуки разной частоты, звуки разной громкости, вода разной солёности, отрезки разной длины, квадраты разного размера, цвет, яркость, вибрация на теле, кривизна, длина и направление линий.
Оказалось, что в зависимости от вида воздействия человек мог отличить от 3 до 15 воздействий.
Многомерные воздействия
Далее Джордж задался вопросом: Как же мы отличаем, например, сотни и тысячи лиц? Дело в том, что лицо, скажем, отличается от другого по множеству параметров, а с увеличением количества параметров ёмкость канала человека прилично возрастает.
Тоже самое и со словами. Почти не зависимо от языка слова отличаются друг от друга 8—10 параметрами, поэтому их никто не путает.
Джордж снова рассмотрел несколько исследований. Например эксперимент Леммера и Фрика показали, что люди могут спокойно отличить 24 положения точки в пространстве (два измерения).
Итак по абсолютным суждениям: для одномерных воздействие ёмкость абсолютных суждений находится в районе семи. Это ограничение легко снимается, если:
а) заменить абсолютные суждения на относительные,
б) увеличить количество измерений (это увеличит ёмкость как минимум до 150).
Но есть еще и пункт «в» — можно организовать задание так, чтобы нужно было делать абсолютные суждения пачками. Об этом далее.
Ёмкость кратковременной памяти
«Все знают, — пишет Джордж, — что емкость кратковременной памяти ограничена и составляет примерно семь элементов.»
Сюрприз, оказывается это обнаружил кто-то другой :)
Далее Джордж, изучив еще несколько исследований показывает, что, не смотря на то, что число семь фигурирует и в исследованиях ёмкости канала передачи человека и в исследованиях кратковременной памяти, это совершенно разные ограничения возможностей человека по обработке информации.
Ёмкость канала ограничена количеством информации, а ёмкость памяти — количеством элементов. Далее Джордж, опять основываясь на исследованиях, объясняет, что элемент в кратковременной памяти может, в принципе, содержать сколько угодно информации.
Итак
1. У человека есть два ментальных ограничения: ёмкость канала передачи и ёмкость кратковременной памяти.
2. Ёмкость канала передачи ограничена количеством информации, а ёмкость кратковременной памяти — количеством элементов (внутри элементов информации может быть сколько угодно).
3. Хотя это разные ограничения их ёмкость находится в районе семи.
4. Увеличить ёмкость можно организуя воздействия в группы или увеличивая количество измерений.
И какая нам от этого польза?
Да почти никакой, если только вашим пользователям не нужно определять соленость воды на вкус или вы не заставляется их запоминать, скажем, цифры и куда-то переписывать из головы. В этих случаях — да, больше семи стаканов не предлагайте и больше семи цифр не давайте.
В остальных случаях исследование 7±2 не должно вас волновать никак.
P. S.
В завершении приведу письмо жертвы 7±2 и ответ самого Джорджа. Moses — это Моисей, а Commandments — это заповеди. Наслаждайтесь:
From: Mike Halpern
To: George Miller
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
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 billiard 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 billiard 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.
From: Mark Halpern
To: George Miller
Subject: RE: citation for your disclaimer
Deaf Professor Miller,
Thank you for full and prompt reply; just what I was hoping for. Armed with your
words, I may be able to convince my boss that your paper does not support the
notion that if a procedure has fourteen steps, you have to divide it arbitrarily
into two procedures, each meaningless in itself.
In being able to quote you against his misinterpretation of your work, I feel
like Woody Allen in that movie where he gets into an argument with a pretentious
know-it-all about some thesis of Marshall McLuhan's, and has the pleasure Of
bringing into the scene the real McLuhan, who tells the know-it-all that he's
completely wrong, and Allen is right.
To: George Miller
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
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 billiard 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 billiard 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.
From: Mark Halpern
To: George Miller
Subject: RE: citation for your disclaimer
Deaf Professor Miller,
Thank you for full and prompt reply; just what I was hoping for. Armed with your
words, I may be able to convince my boss that your paper does not support the
notion that if a procedure has fourteen steps, you have to divide it arbitrarily
into two procedures, each meaningless in itself.
In being able to quote you against his misinterpretation of your work, I feel
like Woody Allen in that movie where he gets into an argument with a pretentious
know-it-all about some thesis of Marshall McLuhan's, and has the pleasure Of
bringing into the scene the real McLuhan, who tells the know-it-all that he's
completely wrong, and Allen is right.
members.shaw.ca/philip.sharman/miller.tx
Какой-то перевод письма можно прочесть на странице lazarev.biz/2008/09/12/miller/.
P. P. S.
Да, вот же еще старый опрос в блоге есть.
UPD
О! Тафти тоже читал это исследование. Он гораздо чётче сформулировал:
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.)
"Williams College to Honor Eight Renowned Scientists," September 23, 2000.
-- Edward Tufte, April 20, 2003
www.edwardtufte.com/bboard/q-and-a-fetch-mNow 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.)
"Williams College to Honor Eight Renowned Scientists," September 23, 2000.
-- Edward Tufte, April 20, 2003