Information Technology Reference
In-Depth Information
The appearance of the graphics we see on the screen or
printed on a page
The time it takes for materials to download on the Internet
An awareness of data representation and its consequences can
guide us as we develop our own materials and as we use the materi
als of others.
represented inside computers?
You scanned an image of your cats, Shamrock and Muffin, and
put it on the Web, and now you want to print out a copy. Because
you're also burning a CD, sending messages to your friends, and
watching a soccer game via Web cam, you have a lot of applications
open and running. As you try to print the image, you encounter two
problems: First, your computer is taking a very long time to open
the image on your Web site, and second, the printed image doesn't
look nearly as good as the one on the Web. To help your situation,
it would be useful for you to have a better understanding of how the
image you're working with is stored and how the computer is work
ing to process your information. For many applications, processing
within a computer involves tradeoffs among speed, accuracy, capa
bility, and size. For example:
If you were using your computer to perform large calcula
tions, you could achieve limited accuracy (think about how
rounding numbers sacrifices the accuracy of a calculation, but
on a larger scale) relatively quickly and use relatively little
storage space, but greater accuracy may require considerably
more time and/or space.
Some wordprocessing applications increase their speed or
their demands for storage by compressing the size of the data
they store, limiting the range of characters in which they al
low data to appear. Restricting data to the simple Roman al
phabet with relatively few punctuation marks, for instance,
prevents the use of additional symbols (e.g., the Greek letter
∂
)
that can be cumbersome or impossible. Such issues vanish
with other storage approaches, but these may require much
more space and more time for processing.
