Here’s a link to a scan where the OCR doesn’t clobber the image http://mrserge.lv/assets/human-factors-engeneering-studies-o...
The lowest errors and fastest keying rate were actually with the standard circular telephone arrangement (most familiar), followed by the two-row five-column layout, and those were also the test subjects’ preferred layouts. In the final test between the 3x3+1 grid vs. the 5x2 grid, the vote tally was 12-3 in favor of the 5x2 gris.
I assume the company’s final choice was based on some engineer or manager’s aesthetic preferences or non-human-factors technical criteria (e.g. it fit better on a particular phone body design), though I’ve never seen any concrete explanations of how the final grid layout was chosen. Or in other words, we still don’t have a solid answer to the question “Why are the numbers on a telephone keypad arranged the way they are?”
> The Automatic Voice Network (AUTOVON) was a world-wide American military telephone system. The system was built starting in 1963,
Something along the lines of http://i.imgur.com/ofeQEC9.png
This is much better (faster, more comfortable, fewer errors) in my experience than the number row at the top of a keyboard, or a standard 3x3 + 1 grid calculator, computer, or phone keypad.
Also, remember that they had a lot of left over molds for rotary phone designs, and they probably intended to retrofit pay phones with rotary dials to touch tone. 3x4 layout fits a lot better into a circle than 5x2 or 6x2.
Numeric keypad layouts mimic calculator layouts, which in turn, mimicked the original ‘adding machines’. The inventors of these early devices did not perform extensive user based testing (as it often the case in technology; early adopters end up creating standards that others follow, good or bad).
The whole point of the article is the Bell labs undertook an extensive user based study to investigate which layouts might be better (Pretty much the first time this testing had been done on this issue). They tested both canonical forms of the (3x3)+1 layout and selected what we now know today as the telephone layout. (If I had to speculate as to why this layout performs slightly better than the calculator layout, I might suggest that, in the West, we read left->right and top->bottom and so this is the more natural numbering scheme).
Had extensive testing been performed by the original adding machine developers, maybe both devices would use the same layout.
Interestingly, the most creative benefit I’ve heard for keeping the calculator layout as it is, is because calculators are often used to sum up real world measurements, and these fall under to purview of Benford’s Law* Because of this, the keys which are more likely to be used as the leading digits are closer to the at-rest position of the hand and require less energy to move and press … yeah … I’m not convinced either, but it sounds good
I don’t think the standard calculator numpad layout is defensible on digit or symbol frequency grounds.
Even if we want to keep the numbers in the standard place for the sake of familiarity, I would recommend adding some keys and relocating others, something like
The lack of them means there's a whole DTMF "column" gone. DTMF works on a grid. When you press a key, the tone for the row and the tone for the column are played simultaneously:
(Hz) 1209 1336 1477 1633
697 | 1 | 2 | 3 | A |
770 | 4 | 5 | 6 | B |
852 | 7 | 8 | 9 | C |
941 | * | 0 | # | D |
If the author of the post is reading this, the image of the two vertical columns is wrong. On the site it's essentially two columns, in the paper it's five rows. That is rows 15 26 37 etc compared to 12 34 56 etc. It makes for a surprisingly large difference, at least to me. The former looks completely unusable, the latter seems quite ok :-) So maybe I should not be surprised that the two 3x3+1 setups didn't perform the same...
(This is why the emergency number is 911 in the US, whereas it used to be 90000 where I'm from)
Anecdote number two is that when I was working in Denmark in 2004 or so, I noticed that all the number pads on credit card readers were calculator-style, not phone-style, which was a legacy from when Dankort was rolled out in the early 80's, just before keypad phones surpassed rotary dial phones.
(In 2010 or around there, most retailers switched their card readers to phone-style layout, so all stores had to have small signs apologizing for it, but mentioning that the rest of the world had phone-style layout, so let's just all get in line with the program...)
The emergency number used to be 000, but it was changed to 112 to match the rest of the EU.
Swedish original on top, US market models on the bottom.
Superior ergonomics & one of the reasons I dislike modern smart cough spy-phones. The audio is shite and software keys are no replacement for actual tactile feedback. Luckily they (rotary dial 800 series) are still available ~ http://www.vintagephones.com.au/ccp0-catshow/refurbished-tel...
1 = 1 pulse
2 = 2 pulses
0 = 10 pulses
Or else they'd all be offset by one
Later on, the phone regulations were changed, and you could own a phone. That's when cheap pushbutton phones came out, that had a switch allowing you to choose between pulse and tone dialing, because you still had to pay more for touch-tone service and some regions didn't offer it.
The weird thing was, sometimes you had to use both, for instance at my college, the phone system used pulse dialing, but I had to enter a "calling card" code using tone dialing in order to call my parents and put the call on their bill.
There were phones out there that had a keypad but only supported pulse dialing too; if I remember correctly, my parents had one when I was a kid.
I expect that the bias to the winning phone design came because of the bias in phone numbers - that is, because rotary dial phones would dial lower numbers more quickly, lower numbers were more sought after, and were allocated to higher population areas. This was both for personal convenience, and because it tied up the phone lines for less time with the dialing pulses.
I expect that this asymmetry also introduced a bias toward the 1-on-top dialing pattern that won, though I don't see analysis to that effect. (The original paper simply stated "that the arrangement frequently found in ten-key adding machines...was not the best [in its group]...the same geometric configuration with a different numbering scheme [one on top] was superior in keying performance... However the performance differences between the two were small".
Of course, the two arrangements primarily differ in which keys are obscured by your hand, and the proximity of the 0 key, which shouldn't be commonly used, so maybe this is just post-hoc reasoning...
We humans get used to the speed as little as it is and having to go back to the old way and it's only 1/2 or even 1/10 second slower drives us crazy.
For medium numbers kaching ticka ticka kaching, for the first numbers 1, 2, 3 it was really quick like tick tick tick.
The zero or even 7, 8, 9 seemed to take so long compared to the other numbers.
Note btw that it ran Series 60, meaning Symbian. Meaning that for all intents it was a smartphone.
And while not circular, Siemens also had a oddity:
And yep, that one is also running Symbian with the Series 60 UI (licensed from Nokia).
Should actual calculators adopt the phone layout, too? I've always been curious why not all devices use the same order (PIN entry pads, phones, calculators, etc.)
None of the calculator companies had the budgets or human factors research experience to do the kind of analysis that Bell Labs did (including some of the earliest true NUI UX research), so they just picked whatever design made the most sense to their engineers .
Edit: correcting the quote to "significantly shorter" from "much shorter"
oh my god. I'm old.
Different technology shapes language.