Computers (along with other information-handling systems) process
data to produce some form of useful output. To do this, a computer needs some
data to be fed into it - this is the INPUT. There are a number of different
ways in which a computer can accept this input. Most methods, though, fall
into two main areas: manual input methods (entering data by hand); and automatic
input (such as data logging).
1 Manual Input Methods
The main manual input method for many people is the
QWERTY keyboard - the one shown here has 105 keys which allow the
user to enter both upper and lowercase text, numbers and some special
characters (such as £ $ % ^ &).
The keyboard is a direct decendent of the keys on a typewriter. The
typewriter was invented in 1872 and was once a very common machine
for producing formal text. The keys on a QWERTY keyboard were originally
arranged so that common letter pairs (such as 'TH' and 'UN') weren't
together. This meant that the mechanism that printed the letters was
less likely to jam.
People got so used to using this keyboard layout that it continued
to be used in the modern computer (or word-processor) keyboard.
As graphical user interfaces (like Microsoft Windows
and Mac's OS X) became more popular people needed a way to point to
different menus and icons on the computer screen. Although you could
use the cursor keys on a keyboard it was much easier to use a mouse.
The mouse was originally used by designers who wanted to draw simple
shapes on the computer screen, for example, during Computer
Aided Design (CAD) applications.
Nowadays, designers and artists use a graphics tablet
to work on the computer. A graphics tablet is made up of two main
parts: a pen (or stylus) and the tablet itself. If you draw on the
tablet with the special pen then your drawings can be converted to
lines and shapes on the computer screen.
It is much easier to draw lines and shapes with a pen (as we have
all used pens since we were little) so many people prefer them to
using a mouse.
Modern paint programs allow the artist to change their pen strokes
into pencil lines, brush strokes, airbrush sweeps and other effects.
In this way an artist can use a variety of tools while holding the
Another way to get graphic images into a computer is
to use a scanner or digital camera. Some artists prefer to use this
method as it enables them to work using their brushes and pens on
paper or canvas before scanning the images into the computer to complete
using specialised software (such as Adobe's
The concept keyboard is a touch sensitive board that
can be connected to a computer. The useful thing about the concept
keyboard is that different sheets (or overlays) can be placed on top
of it and the person using the keyboard can use their fingers to press
the pictures on the sheet.
The keyboard in this picture has been used with children
who are learning to read and write. The child can press the pictures
on the keyboard and the word for that picture appears in a word processor
on the computer.
Similar keyboards are also used at shop tills (such as fast-food outlets)
because pictures of the food on offer can be placed on the keyboard.
The keyboards are easy to keep clean and can be changed if a new product
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2 Direct (automatic) Input Methods
There are some situations when it would be impossible
(or very impractical) to enter data by hand. The National Lottery
scheme uses Optical Mark Readers (OMRs) to convert
the marks that you make on a lottery ticket (shown here). This is
because the OMR machine is much more accurate than someone with a
keyboard would be.
It may seem easy to enter six numbers (all under 50)
without making a mistake. But, if you have to do this hundreds of
times a day, for a queue of grumpy customers then you may well make
a mistake. If that mistake meant that your customer did not win the
jackpot then they may get a little grumpier!
On the other hand, if you want to measure certain conditions
for very long or very short periods of time then you need a data-logging
Although you could stand outside for a week measuring the air
temperature with a thermometer (and writing the results in a notebook)
it is far easier - and more accurate - to set up a data-logger to
record the temperature for you. The data-logger will not get bored,
miss a reading, or need to stop for food or the toilet.
Why not go to the data-logging
page and look at some examples of data-logged data ?
Both the data-logger and the OMR machine are devices
for collecting large amounts of data accurately and entering them
directly into the computer.
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