The magic rule of 7 in online forms | Hacker News Reader

The magic rule of 7 in online forms

sethgodin.typepad.com

12 pointscwan22 comments

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."

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.

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.

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."

This must surely be one of the most abused statistics of all time, and Seth is generously keeping the myth going.

If you want to look up the original research, and get some idea of when the conclusions are relevant and when people are just quoting statistics without really knowing what they're talking about, you could start here:

http://en.wikipedia.org/wiki/The_Magical_Number_Seven,_Plus_...

This is a myth that just won't die: http://en.wikipedia.org/wiki/The_Magical_Number_Seven,_Plus_...

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

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?

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.

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.

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).

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

See http://en.wikipedia.org/wiki/The_Magical_Number_Seven,_Plus_...

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?

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.

I've found that just having folks enter free-form information works amazingly well too.

The caveat is that you have to make sure error handling sucks a bit less; otherwise, you run into people getting frustrated that their country isn't listed or that they're using a foreign name for it or similar.

... or maybe you could dump those cases into a customer service bin straight away and have those folks talk to a real human to straighten things out.

A better alternative might be just to list the name of the country the users's IP address is originating from, in no input field, just as text - with some button or method of changing it - that could bring up a nicely organized/filterable country list.

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

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'.

I think the second part of that post applies (as to avoiding alpha order and making it easiest for the user). I think it makes sense to look at where users come from and list them accordingly. Maybe there's a bit of bias here but I find the ones that list the US, Canada first to be more useful (though one of the problems is that it is perceived as arrogant by foreigners but then again I'm Canadian).

Another alternative is to default to the country from which the IP address originates - but I'm not a programmer and don't know how difficult that is.

How many countries do you list first, though? I find those forms annoying - the US and Canada sit at the top of the list, but then to find the UK I have to go down and look near the United Arab Emirates or Uruguay or some such place.

But then, some forms have "Great Britain", others just "Britain" and some split us into England, Scotland, Wales and Northern Ireland. It can take minutes just to find my country and I do wonder how many people just give up and never sign up or finish the check-out.

Again, not being a programmer, and obviously there's a bit of cost-benefit involved here, is it possible to put the default under the pre-set non-alpha list? Usually I can type in the first few letters to have it skip to the country I'm searching for if they're listed in alpha order. I tend to type the first few letters to see if this works first but then if I use the drop down I see the unordered select few countries above this default.

thaumaturgy also suggested a great alternative. Though in doing the autocomplete/alpha list, I would list each of Great Britain, Britain, England, Ireland, Scotland, Wales and Northern Ireland so as to avoid the problem you describe.

Group by continent.

Organizing a flat list of 50 items into 7 groups of 7[1] should improve accessibility, if the categories make any sort of sense. I would be interested in seeing research comparisons of flat dropdown vs grouped dropdown (ie some items are unindented unselectable categories) vs double-dropdown, where the items available in the second are determined by the selection of the first.

[1] For the purposes of dropdown menu length, 49 is equal to 50.

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