The first commercially successful typewriter was developed by Christopher Latham Sholes in 1873. Originally, the keys were arranged alphabetically. However, a problem soon arose. People became so adept at using the keyboard that the keys would stick or jam when struck in quick succession. In order to overcome this problem Sholes decided to make the job of typing as slow as he possibly could. His solution? He placed the most frequently used keys as far apart from each other as he could. His keyboard became known as the QWERTY keyboard.
So, that maybe is the reason why your keyboard is formatted the way it is. Ironic, considering that every other aspect of your computer is streamlined for maximum efficiency and yet you have to labor over a 127 year old system designed specifically for inefficiency. And inefficient it certainly is. For one thing, QWERTY was not designed for touch typing (also called keyboarding) , which came much later. For keys that are not in the middle or home row it is necessary to reach across diagonally. This is difficult and leads to a high error rate.
The standard QWERTY keyboard has dominated for many years as the chosen option for letter arrangement of keys despite the fact that this arrangement did not have its origin in ergonomic experiments or use surveys. Because of its extremely wide usage and standardization as a population stereotype.

i am a product design student from National Institute of design. i am looking into this matter and planning to design a new input device for more efficiency.
also computers have become personal so y not our input devices. what if they know what exactly we want?

help me in knowing what do u expect form this new input device?
what all problems u face while using.?
and what all would u like to have in it ?
is there any particular technology u looking forward?
future of input devices?

I want mechanical switches mounted on silicon boobs. It's so ergo!

Welcome to Geekhack!

The problems of the QWERTY keyboard are well known.
The first "ergonomic keyboard" that I know of is the Burboa Type Writing Machine, US patent 1089689 Mar 10, 1914. Several ergonomic keyboards throughout the years have similiar layouts -- whether they know it or not.
Several alternative logicallayouts -- but still for the physical layout of the QWERTY keyboard have emerged: Dvorak, Colemak, Dhiatensor etc.. and many of them in the age of the typewriter.
When computers emerged and became popular in the 1970's, there were many studies on which properties that were desirable. You may find those papers and book under the heading  Human-Computer Interaction, but I'll tell you the most important finding: feedback is very important. The need for accurate feedback will not go away.
People type faster and more accurately if they can feel the keys before pressing them, feel when the key has actuated and .. if they can hear when it has actuated. Those properties are why so many members here like "clicky" keyboards with full-sized keys, abhor flat,  "chiclet" keyboards .. and sneer at touch screens.
Many of the properties of so-called "ergonomic" keyboards have emerged not to make typing faster, but because of medical problems that the typists have developed: Repetitive Strain Injury, Carpal Tunnel Syndrome etc.

Some  members here are very good at identifying problems with keyboards themselves and to construct new, more ergonomic keyboards. Just search for the Symmetric Stagger board, the Humber Hacker keyboard and the Key64.
My personal quest is to build "The ergonomic keyboard for the rest of us": which incorporates what I have learned about keyboard ergonomics into a keyboard that looks more like a "standard" keyboard and which you don't need to be able to touch-type to use it.

One problem with keyboards, on a higher level,  is that today we use both a keyboard and a mouse, and it is a hurdle to switch between them.
Because of this, you can often see people "hunt and peck" with the left hand on the keyboard and rest the right hand on the mouse. That may work for some applications but not when you need to type a lot.
Part of the problem is that there is a lot of distance between the main keyboard and the mouse. The keyboard layout that is dominant today was introduced by IBM with its Model M .. before the mouse. Cursor keys and numeric keys were to the right of the main keyboard. IBM had been influenced by DEC. DEC's keyboards were part of bulky "terminals" where the small monitor was on the left side inside the unit with the main keyboard centered in front of the monitor. That made DEC put any extra keys on the right side where there was space.
The solutions that we have seen for this include: smaller keyboards w/o extra keys to the right, so called "left-handed keyboards" with the extra keys to the left, keyboards where the left-hand keys are on the mouse, trackpoint or trackball in the middle of the keyboard, Rollermouse, trackpad, Mousetracker (mechanical trackpad) and one-handed keyboards such as the Matias Half Keyboard, Frogpad, etc.

Also, today we not only type, point and click. We also scroll a lot. There are keyboard models today that have scrollwheels, (even though scrollwheels are relative to mouse focus and not keyboard focus). We also use the cursor/Home/End/PageUp/PageDown keys for scrolling. This is also something that you could focus on.

I'm always skeptical of that story about Qwerty being designed to be as inefficient as possible. If it truly was inefficient, people wouldn't be able to type on them at 120+ WPM as some do. Also, they way I've always seen it is even if it is faster to type on a Dvorak keyboard once you learn, you're going to be dealing with Qwerty keyboards wherever you go for the rest of your life whether you like it or not, so it'll probably just end up screwing with your typing. Colemak does improve upon this by being much easier to learn (and arguably better) than Dvorak, but for most learning a new layout will be too much effort. Although I do believe the actual physical layout of the keys could be improved upon (like the TrulyErgonomic keyboard is trying to do, for example), but it won't truly work until an improved layout is widespread.