Information Technology Reference
In-Depth Information
late Web pages within a database. When you request information
on a particular topic, the search engines identify relevant Web pages
according to their indexing. Algorithms then order these pages ac
cording to their perceived relevance, based on a variety of criteria.
Commercial sites gain business according to the visibility of
their Web pages, and this may lead companies to adjust their mate
rials to manipulate ratings and perceived relevance. Popup boxes
and browser scripts can be used to supplement information at your
browser, for error checking, and to enhance product visibility.
Email started in the mid1970s as a mechanism to send simple
messages, but the MIME format now allows the transmission of
multimedia materials. When you receive email, your mail program
can display what it receives, but data in messages, such as the
sender, can be faked; you cannot have confidence about who sent
an email. Commercial companies may collect email addresses from
many sources and guess about other email addresses. With lists of
potential email addresses, marketers may broadcast unsolicited
email or spam in great quantities as an inexpensive way to adver
tise products to large audiences.
Both Web pages and email can contain programs, including
viruses. Although laws can provide some help in controlling un
wanted programs and spam, your best defense involves caution and
vigilance.
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Terminology from This Chapter
event
eventdriven
programming
indexing
infinite loop
Multipurpose
Internet Mail
Extensions
(MIME)
spam
Web crawler
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Discussion Questions
1.
An assignment in one course asked students to write a paper
describing an application of a particular type of algorithm.
One student typed the name of the algorithm into a search en
gine, examined one of the references returned, and wrote a
paper explaining that application. It turned out, however,
that the referenced application had nothing to do with the
