Information Technology Reference
In-Depth Information
not predict the stock market?
From the first chapter of this topic, I have emphasized that a
computer functions by following instructions, based on a relatively
few builtin operations. For example, it can move data from one
place to another—as needed for the storage and retrieval of data; it
can perform basic arithmetical and logical operations—such as ad
dition, subtraction, multiplication, and the comparison of numbers
or letters to see which is bigger; and it can follow instructions
quickly.
These capabilities are the foundation for all computer applica
tions, including word processing, databases, spreadsheets, Internet
banking, and Web browsing. When we buy or utilize existing soft
ware written by someone else, we may not think about the internal
details. However, behind the scenes, someone (or a team of some
ones) has carefully thought through just what steps are needed to
perform a task, and those steps have been specified in a program in
remarkable detail. For example, even if we do not know just how to
tally a budget or compute our taxes, we can still accomplish these
tasks because someone, a program developer, has done the work for
us in writing a program.
In general, to perform any task with a computer, a program de
veloper must specify the individual steps required to accomplish
that task. This list of steps is called an
algorithm
, and the thought
process of identifying and presenting those steps is called
algorith-
mic thinking
. Since the algorithm is the basis for all computer activ
ity, identification of an algorithm might be considered the most ba
sic part of using a computer to help solve a problem.
Let's examine algorithms by taking a look at the launching of
astronauts into space. In this endeavor, one must consider a remark
able number of factors: burning of rocket fuel, magnitude of burn,
directions of the rocket and rocket thrusters, forces of gravity,
masses and velocities of gases and the rocket itself, interactions with
the atmosphere (e.g., friction with air, wind forces), and more. The
full list of variables could fill volumes, but all ingredients follow ba
sic laws of physics, and all activity can be charted through appro
priate mathematical equations. The fact that each variable can be
