Why are keys arranged like stairs?

[thrab]

I prefer my keys to be all the same height. I am not sure why most higher quality keyboards have a huge stair style going on. Of the styles below I like LP the best. So what is the rational of all these weird steppings? Is just a hold over from the typewriting days and has no real benefit to anyone anymore?

[thrab]

Is there any logical reason though? You know, one other than "That is just how it is".

[Tony]

Why your hand has five fingers with different length?

[msiegel]

Rest your fingers on the home row, and then stretch up and down to reach the other rows.

With stepped rows the keytops are almost the same distance from your fingertips, so you don't have to flex your nearest finger joint as much.

[msiegel]

Why your hand has five fingers with different length?

http://knowyourmeme.com/memes/how-is-babby-formed

[thrab]

Why your hand has five fingers with different length?

But the fingers being different lengths would not make the step pattern we see. There is a keyboard floating around that moves the keys forward/backward from the normal positions to accommodate different finger lengths but those too seem to follow the stair pattern.

[thrab]

Har har

[majestouch]

Practically, this arrangement limits the distance you need to move your hands from the home row to reach keys near the top or bottom of the board. Imagine a side-view of your fingers typing, much like the pendulum swinging from a fixed point pictured below; i.e.



If your keys are the same height, the fixed point (your hands viewed from the side) must be shifted farther left or right in order for you to be able to reach the keys on the top or bottom rows, BUT with a curved or stepped arrangement your hands needn't move so much and can stay closer to the home row.

Less movement to and fro can probably be easily shown to increase touch-typing accuracy and efficiency; sorry no reference, just shootin' from the hip:)

[quadibloc]

The motion of the fingers on a center explains why keyboards are contoured.

It used to be, though, that keyboards were stepped without being contoured, until the Selectric typewriter introduced the contoured keyboard.

Why shouldn't they be contoured without being stepped, though? That's a legitimate question.

One reason is that by stepping the keys, when the fingers push down on the keys (and it's a natural assumption that down is the right way to press) they're applying a more perpendicular pressure to the surface (less tendency to slide off).

[keyb_gr]

The use of curvature is quite easily demonstrated. All it takes are an "all curved" keyboard (like a Model M or similar Keytronic or old Fujitsu) and another which is all flat. Now put your fingers on the home row and try reaching for one of the F keys, like F1, or even Esc. Hand travel will be noticeably larger on the flat keyboard.

[cbf123]

It comes from the the motion of the finger.  When typing on a key you must first move your finger to the top of the keycap, then press down.

Stepped keys and/or angled keycaps help with this.

[thrab]

The travel argument has no basis in logic. Look at this simple elementary drawing using trig shown below. It clearly shows level keys being more efficient in terms of travel. As for the curvature of the top of the keycap itself (like DSA vs. LP), I also like this and think it adds to stability without detracting from travel efficiency.

[wanabe]

I think you are misunderstanding the travel argument.  imagine that your fingers as pendulums that swing from the front of your hands.  When you hover over the home row and reach up for the numbers, having the keys raised makes them closer.

[thrab]

I think you are misunderstanding the travel argument.  imagine that your fingers as pendulums that swing from the front of your hands.  When you hover over the home row and reach up for the numbers, having the keys raised makes them closer.

My fingers do not do this and I do not use the home row. The pendulum argument acts like the finger cannot move in multiple ways simultaneously.

[thrab]

High pot in use.

Unfortunately no, in USA :nono:

[wanabe]

of course fingers can move in all directions, but we're talking about efficiency of movement here. it's by design that that only makes sense if you're using the home row.

[thrab]

Most do, some don't. If that's the argument for stairs I'll go with it... I just think it is kind of weak.

[Sheepy]

Its a design for comfort/optimization.

A desk usually runs parallel to our arms, but our fingers are usually still spread horizontally. So the keys are arranged so that the keys furthest away are where the finger is most stretched out and the lower keys for when you're pressing down at more of an angle. Basically to reduce the need for us to bend our fingers at a near right angle. Even if you "don't use the home row" your hands are usually going to be in the middle of the keyboard. Obviously its not that different to a flat key setup but its more a subtle optimised design.

Also the distance thing does make sense. You're calculating the distance, but you didn't take into account that people have fingers. If its a flat keyboard and you're trying to press 2 keys at the same time, if you're all the way stretched out you arch your finger and thats where you lose the distance. Where as on a stair thats less of a problem because its slightly raised up to you and the levels are seperated?

I hope people understood that, its kind of hard to demonstrate without pictures, but it makes sense, because of lots of little things im not even going to bother explaining because Im yapping on here lol

[kps]

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Ya damn kids, get off mah lawn.