Jeff,
Thanks for your question.
Like you, I find it hard to believe that no major search engines make
use of a wildcard function, and that the one search engine that used
to have it (AltaVista) chose to abandon it.
It b*ggles the mind!
It's hard to know what the reason is. It may be the case, as has been
suggested already, that use of wildcards creates a lot of server
demand. I suspect a more likely reason is that casual users of search
engines simply don't use wildcards, nor do they perceive a need for
them. In the absence of a real demand for the service, they simply
have not been pursued by the major search engines.
Then, too, search engines have become ever-more sophisticated at
automatically stemming, at including synonyms and other related words
in searches, and in recognizing and correcting spelling errors. All
these techniques have lessened the need for wildcards.
For instance, you mentioned that wildcards are necessary since "Nobody
can be sure of the spelling of every word" However, the ability of
search engines to "guess" at the intended meaning of a mis-spelling
has gotten awfully good in the past few years.
Still....there are a few options available to you regarding actual
wildcard searches.
First of all, there is a wildcard, of sorts in Google. The asterisk
character can be used in place of any single word (rather than a
single letter).
I know your question was about replacing letters, rather than words
(and more on that below). But the Google asterisk is a good tool to
be familiar with just the same, and is best used in combination with
exact-phrase searching when you're not quite sure of the exact phrase.
For instance, a Google search of [ "top 100 * cities" ] returns listings for:
Top 100 Canadian cities
Top 100 Unwired cities
Top 100 Biggest Cities
and even the
Top 100 Sweatiest Cities
===============
The Exalead search engine -- mentioned by pinkfreud-ga -- is the only
mainstream search engine that I know of that has an actual wildcard
function that can substitute for missing letters.
However, I have to warn you, I've found Exalead to be hit-or-miss in
the times I've used it for specialized functions -- sometimes the
results are superb, and are unlike those from any other search engine.
But at other times, I wind up with fairly garbled results that aren't
much use. You'll have to do some experimenting.
In addition to simple wildcards, using an asterisk [ * ], Exalead also
allows for complex searches using what are known as "regular
expressions" (in fact, wildcard searches are generally a specialized
form of regular expression searching). Regular expressions are very
difficult to learn to use, but once mastered, can provide very
powerful search strategies.
The instructions for Exalead advanced searching -- including wildcards
and regular expressions -- can be found here:
-----
http://beta.exalead.com/search/C=0/?2p=Help.2
Prefix search allows you to find documents based on the beginning of a
word. This operator allows for instance, to find a proper noun from
its shortened version, or to search on the linguistic root of a word.
Jenn* Searches for documents containing words starting with Jenn:
Jennifer, Jennie, Jenni, Jenna, etc.
develop* developing, developed, development, develops, etc.
Patterns
Exalead supports regular expression patterns. Patterns are introduced
by a slash ('/') character. Within a regular expression, '.' is a
special character that can represent any character, '*' stands for
character repetition, '|' stands for 'or', and parenthesis are used to
group characters. '?' is placed the end of a character group to make
it optional.
/s.ren..pi.y/
Searches for documents with words that match the pattern S . R EN ..
PI . Y -- this can be very useful to finish your crossword puzzles!
/mpg(1|2|3)?/
Searches for documents containing any of the following: mpg, mpg1, mpg2, or mpg3.
-----
To really take full advantage of the wildcard and regular expression
functions, spend some time playing around with Exalead, and using the
examples provided above. It can be a very cool search experience
(when it works!).
===============
A specialized blogging search engine known as Blogdigger:
http://www.blogdigger.com
also seems to offer limited support for a wildcard functions, with an
asterisk [ * ] as the stand-in for a single character.
For instance, a search on [ w*shington ] will return hundreds of
thousands of results, appropriately focused on [ washington ].
However, not all searches using asterisks are equally satisfactory.
Like Exalead, this may be something of a hit or miss function.
===============
The best wildcard searches can be done using commercial sources that
are independent of search engines. For some reason, search services
like Lexis-Nexis are fully aware of the value of wildcards, even
though search engines seem to have missed this entirely.
Lexis-Nexis is not a free service. HOWEVER, you CAN search their
databases for free -- using wildcards. If you want to actually
retrieve the full documents, then you'll be required to pay a fee of a
few dollars for each document. Not as satisfying as a free search
engine, to be sure, but still, there are times when the flexibility in
searching may be worth it.
First, head to their main page at:
http://www.nexis.com/research
and on the right-hand side of the page, you'll see a hyperlink for
"Not a Subscriber". Click on this, and the system will take you
through its registration process (you'll need you credit card of
course).
Use the "Pay As You Go" option when given the option (but you won't
have to actually pay anything unless you order a document).
Finally, you'll get to the "search page" where you are given an option
to search a variety of topical databases. Pick the databases of
interest (e.g. news), and you're off.
The wildcard characters in Nexis are [ * ] for a single character, and
[ ! ] for multiple characters. For instance, a search on [ bath! ]
will find articles with bath, bathroom, bathing, etc.
===============
Lastly, there are many specialized sites on the internet that support
wildcard searching for a specific database. For instance, if you're
interested in American history, head to the Making of America site at:
http://www.hti.umich.edu/cgi/t/text/text-idx?sid=51a383ba92f628c53fc4594f9f2992d6;xg=1;page=simpleext;ALLSELECTED=1
and note their instructions on using an asterisk as a wildcard just
beneath the search box:
[ work* finds "worker," "working," etc. ]
I trust this information fully answers your question.
However, please don't rate this answer until you have everything you
need. If you would like any additional information, just post a
Request for Clarification to let me know how I can assist you further,
and I'm at your service.
All the best,
pafalafa-ga
search strategy -- Used bookmarked sites for search engines and databases |
