Search Engines & how to use them
QUESTIONS & ANSWERS:
Q: What's an Internet Search Engine?
A: One way of finding information on the Internet
is to use a "Search Engine". This is an Internet tool which will
search for Internet sites containing the words that you designate as a
search term. It provides results back to you in the form of links to those
sites which have the term(s) you're looking for.
For example, if you wanted to see if there were any math
lesson plans on the Internet that you could borrow, you might enter
"math and lessons and plans" as your search term. After a brief
wait, you would receive a web page with dozens of links to sites which had
those particular words somewhere in the site.
It's important to understand that Search Engines DO NOT search the
Internet itself. They DO search databases of information ABOUT the
Internet which the company hosting the search engine has developed. Each
search engine looks through a different database and that's why they each
will reach different results from exactly the same terms.
The degree of detail recorded by Search Engines varies
greatly. For instance, some may enter the entire text of the document into
a searchable field and others may only enter a short description. This is
only one way in which Search Engines differ. Another difference is in the
level of sophistication employed by the search engine when it looks
through its database.
Q: How does a Search Engine know about the millions of documents on
the Internet?
A: Search engines do not search the Internet
itself, but instead search a database of information about the Internet.
Thus, when a document is placed on
the Internet, it will only be found by a search engine if information
about that document has been recorded in the search engine's database.
There are at least two ways a search engine finds out about a document.
One way is for the publisher of the document to register
it with the engine. If a document publisher wants to ensure that a
document is "found" by Search Engines, then the publisher will
usually register with as many engines as possible. The second way that
documents get registered is if the search engine company finds it as part
of its research routines. Some Search Engines use "spiders" or
search robots to search the Internet and gather information which is
subsequently recorded in the engine's database.
Q: What's an Internet Directory?
A: Directories organize Internet sites by
subject, allowing users to choose a subject of interest and then browse
the list of resources in that category. Users conduct their searches by
selecting a series of progressively more narrow search terms from a number
of lists of descriptors provided in the directory. In this fashion, users
"tunnel" their way through progressively more specific layers of
descriptors until they reach a list of resources which meet all of the
descriptors they had chosen.
For example, if you were using the Yahoo subject
directory to find math lesson plans, you would start at the top level of
the directory where there are approximately 15 general categories,
including "arts and humanities", "government" and
"education." Selecting "education" would lead to a
list of about 35 descriptors, including "higher education",
"magazines", and "teaching." Selecting
"teaching" would lead to another page of resources all about
teaching - including "English", "K-12", and
"Math." This last choice would reveal a number of actual
resources for the math teacher.
It's important to understand that a subject directory
will not have links to every piece of information on the Internet. Since
they are built by humans (rather than by computer programs), they are much
smaller than search engine databases. Moreover, every directory is
different and their value will depend on how widely the company searches
for information, their method of categorizing the resources, how well
information is kept current, etc.
Q: What's better - a Search Engine or a Directory?
A: There is no hard and fast answer to that
question. A lot depends on the personal preferences of the user. Some
people like directories because the user can control the search pattern,
varying the path through the descriptors if another descriptor looks
promising. Directories allow users to browse and to be more vague or
general in their search term. Search engines leave the searching pattern
to the computer program and can be used to find more specific resources.
A weakness of directories is that you must depend on the
descriptors provided by the company. If these are not specific enough for
you, then your search may be unsuccessful. As a result, directories can be
good for finding general information, but not too successful in locating
specifics. Also, the number of resources that you can find in a directory
is generally far less than through a Search Engine.
A weakness of the Search Engines is the very extensive
amount of hits that they can produce. A general search term could produce
thousands of hits - far too many to be of much value. Knowing how to
conduct searches is a skill and there is a learning curve. The next
several FAQs provide information on how to develop search skills.
Q: How can I improve my use of Search Engines?
A: You can get better results from an Internet
Search Engine if you know how to use wildcards and "Boolean
operators." Wildcards allow you to search simultaneously for several
words with the same stem. For example, entering the single term "educat*"
will allow you to conduct a search for "educator",
"educators", "education" and "educational"
all at the same time.
(Boolean operators were named after George Boole
(1815-1864) who combined the study of logic with that of algebra. Using
the Boolean operator "and", it is possible to narrow a search so
that you get quite a limited set of results. Another common operator is
"not" which acts to limit a search as well. The Boolean operator
"or" has the opposite effect of expanding a search. Using Boolean
terms, you can have the search engine look for more than one word at a
time).
Q: What's a wild card and how do I use it?
A: A wild card is a special character which can
be appended to the root of a word so that you can search for all possible
endings to that root. For instance, you may be looking for information on
the harmful effects of smoking. Documents which contain the following
words may all be useful to your search: smoke, smoking, smokers, smoked,
and smokes. If your search engine allowed wild cards, you would enter
"smok*". In this case, the asterisk is the wild card and
documents which contained words that started with "smok" would
be returned.
Q: How do I narrow a search?
A: The Boolean operator "and" is the
most common way to narrow a search to a manageable number of hits. For
example, with "heart and disease" as the search term, an engine
will provide links to sites which have both of these words present in a
document. It will ignore documents which have just the word
"heart" in it (e.g., heart transplant) and it will ignore
documents which have just the word "disease" in it (e.g., lung
disease, disease prevention). It will only make a link if both of the
words are present - although these do not necessarily have to be located
beside each other in the document.
For even more narrow searches, you can use
"and" more than once. For example, "heart and disease and
prevention" would limit your search even more since all three terms
would have to be present before a link would be made to the document.
The Boolean operator "not" narrows the search
by telling the engine to exclude certain words. For example, the search
term "insecticides not DDT" would give you links to information
on insecticides but not if the term "DDT" was present.
It is possible to combine two different operators. For
example, the term "endangered and species not owl" would give
you information on various kinds of endangered species - both of the words
"endangered" and "species" would have to be present
for there to be a hit. However, you would not get information on any owls
that are endangered since the "not" term specifically excludes
that word.
Q: How do I widen a search?
A: The Boolean operator "or" will
broaden your search. You might use "or" if there were several
words that could be used interchangeably. For example, if you were looking
for information on drama resources, using just that one search term might
not give you all that you wanted. However, by entering "drama or
theater", the search engine would provide a link to any site that had
either of those words present.
For even wider searches, you can use "or" more
than once. For example, "drama or theater or acting or stage"
would provide a very broad search indeed.
It is possible to combine Boolean operators in a complex
set of instructions through the use of parentheses, however that topic is
beyond the scope of these FAQs.
Q: How do Search Engines deal with Boolean operators?
A: The short answer to that question is -
"not consistently". Some engines allow the use of just a few
operators while others provide access to a wide range. Some require you to
enter the operator yourself while others have you select the operator from
a pop-up box. Some allow you to do any kind of search from the main search
page while others require you to go to an "advanced" page to
conduct Boolean searches.
Some engines allow you to enter several words into the
search term WITHOUT a Boolean operator. However, some search engine will
assume that there is an "or" operator between the words while
others assume the desired operator is "and". Check what the
engine's default operator is before you elect not to enter Boolean
operators.
Q: What's a "meta" Search Engine?
A: A meta search engine is a search tool that
doesn't create its own database of information, but instead searches those
of other engines. "Metacrawler", for instance, searches the
databases of each of the following engines: Lycos, WebCrawler, Excite,
AltaVista, and Yahoo. Using multiple databases will mean that the search
results are more comprehensive, but slower to obtain.
Q: What are some effective Search Strategies?
A: Decide whether a Search Sngine or a Directory
will be the best vehicle. The more specific the information you need, the
more likely you will want to use a search engine.
When using a Search Engine, be as specific as possible.
The amount of information now on the Internet can be overwhelming. To
narrow down your search results to manageable numbers, use a search engine
that allows the use of Boolean operators and enter as many keywords as
possible.
Get used to more than one Search Engines. You will
develop a preference for a certain engine and it may work well for you but
don't forget the other Search Engines and, from time to time, try another
engine or a meta engine to ensure that you have achieved good coverage of
the Internet.
Read the "tips" files provided by most
engines. You'll be surprised to find out little things that make life
easier. For instance, AltaVista allows you to use the "+" symbol
instead of writing out the word "AND" when you use Boolean
operators.
