
The magic rule of 7 in online forms - cwan
http://sethgodin.typepad.com/seths_blog/2009/11/the-magic-rule-of-seven-and-the-banality-of-alphabetical-order.html
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thaumaturgy
With just a little more effort, Seth Godin could fit his blog posts into a
tweet:

"Use no more than 7 of anything in a form, because I believe that human brains
can't handle more than 7 items at a time."

~~~
nrr
That's pretty much what I was thinking while I was reading this.

Well, actually, I thought, "Seth, this is nice and all, but can you provide me
either first-hand experimental results or published results to convince me
that seven is the magic number?" That's close enough though.

~~~
mattlanger
I was also a little puzzled by the _post hoc ergo propter hoc_ tone of his
assertion that "Human beings have no trouble keeping seven ideas in their head
(hence the seven digit phone number)", if for no other reason than that I have
an easier time remembering my social security number than my own phone number.

Positing the existence of the decimal system because humans evolved with ten
fingers is something I can get behind. The seven-digit phone number, on the
other hand, I'd probably attribute to other causes.

~~~
nrr
In his case, it'd probably classify under the fallacy of _cum hoc, ergo
propter hoc_ given the abuse of statistics.

The seven-digit phone number in the NANP most definitely did not come about
because of this; in fact, most quoted phone numbers from the early days of
telephones in the US had _five_ digits. You can see parts of the numbering
plan reminiscent of this even today.

Case in point, I grew up in a St. Louis suburb called O'Fallon, where the
predominant telephone branch exchange was 632. The first two digits correspond
to OF as found on the keypad or rotary dial. From there, the extension was
five digits. Belleville is very much the same way with the 23x exchanges used
there.

If you were calling to someplace out of town, you'd _name_ the branch exchange
and then enumerate the extension. For example, to call the Belleville
municipal police department from O'Fallon, you'd tell the operator that you're
trying to dial "Belleville 4-1218."

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richardw
This is a myth that just won't die:
[http://en.wikipedia.org/wiki/The_Magical_Number_Seven,_Plus_...](http://en.wikipedia.org/wiki/The_Magical_Number_Seven,_Plus_or_Minus_Two)

And why it doesn't apply to UI's: <http://www.ddj.com/184412300>

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jamesbressi
Kinda off-topic, but related:

Did you ever notice that Seth Godin posts drive HN commenters nuts? Keep an
eye on every Seth Godin thought that gets on HN.

It's an odd paradox. If this is the case, then why does every thought make
front page?

Now, I know if you threaten (negatively or positively) someone's beliefs or
behaviors it is good for business (e.g. get people talking), and that may be
why it makes front page every time.

My last question is, don't you ever wonder why he doesn't allow comments on
his thoughts? Maybe he has addressed this before. Is it because he doesn't
want any negativity about his writing, or is it to get on sites like HN to
spread his message?

~~~
jeff18
If you subscribe to his philosophy, it's pretty clear that it's to get people
to spread his message, although I don't think he explicitly says so.

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puns
While less is more in online forms is good advice, the thing about 7 items is
wrong in this context. This is because while you may only keep 7 items in your
head at any time you're not actually using this skill when filling out your
form -- you're just scanning down the list for a particular item you need, not
trying to memorize the whole list. Even if you're trying to choose between
comparable items, you're still memorizing those few items, not the whole list.

~~~
ams6110
Agree, seven is a pretty small and arbitrary limit for a drop-down. I think
maybe 20 or 25 is a better limit, and certainly not so many that they won't
fit on a typical 1024x768 display (less if you're supporting small/mobile
device displays explicitly).

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jauco
It's seven+ items _in your head_ that people have trouble with. if they are
presented on screen that statistic simply doesnt apply.

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motters
See
[http://en.wikipedia.org/wiki/The_Magical_Number_Seven,_Plus_...](http://en.wikipedia.org/wiki/The_Magical_Number_Seven,_Plus_or_Minus_Two)

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naz
Does this apply to country drop downs as well? Pretty much every checkout form
uses a massive list of countries. What should we use instead?

~~~
thaumaturgy
I would _love_ to see auto-complete text entry used in country fields.

Provide the massive drop-down as usual, and then in JavaScript replace it with
a nice auto-complete.

~~~
dchest
Don't drop-downs already have "find as you type"? Focus on a drop-down, press
a few letters.

~~~
ams6110
In most browsers yes. Some, and specifically IE6, this works only for the
first letter of the option, not cumulatively. E.g. typing 'd' then 'e' leaves
the dropdown focused on the first option starting with 'e', rather than 'de'.

