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Info Literacy Curriculum #2 - Basic Search
Transcript of Info Literacy Curriculum #2 - Basic Search
Where did they come from?
How do they work? Let's time travel, way back to... 1994! In the early days of the web, the number of pages
was small enough that it was practical for people to try
to catalog them all. This is how Yahoo! started out, as a human-
curated web directory. Sites like this do still exist, and are good for finding
well-vetted (but not always current) information on
popular and well-defined topics. The Open Directory Project:http://dmoz.org
The Internet Public Library: http://ipl.org However, as the web began to grow... The number of pages quickly became far too large for
people to keep track of. The need for automated tools to do this
for us quickly became apparent. Computers are much faster at processing
information than people are, so lots of
programmers got to work coming up with
ways to make computers do the heavy lifting
of organizing and finding information online. What they eventually came up with was the
SEARCH ENGINE. A search engine is an online program that CRAWLS the web for information,
INDEXES that information, and then allows web users to SEARCH it. What is a Search Engine? Crawling: This is how search engines find pages to index. They
have a program that scans the web and constantly follows links
until it has found as much of what's out there as possible. Indexing: This is how the search engine makes sense of and
organizes the information it finds. How this is done varies, but it
usually involves analyzing and quantifying the words, links, and
other pertinent information found on a web page. Search: Once you have an index, you need a way for users to
interact with it to get the information they seek. This is the part of the search
engine that you actually see and work with. The downside to letting computers organize our information for us is that they
don't speak the same language we do. Speaking Search Search Strategies Case Study: Google Search engines require the use of a
specialized language. How can we
learn to speak it effectively? Try again. Fail again. Fail better. A look at the nuts and bolts,
with Google as our example. Limitations of Search You can't find everything with Google
or even on the open web for that matter. Advanced Search What to do when basic search fails. Try Specialized Search You say Tomato, I say 10101010 Programmers have come up with a lot of powerful
workarounds to try to bridge that gap, but they take
some getting used to. We'll look at the most important of these in this
section. Human language is ambiguous, complex, and metaphorical. Computers on the other hand, are extremely literal. Examples of the sorts of special language search engines use include: Search Dialect Boolean Operators: AND, OR, and NOT. The use of double quotes to search for a specific phrase. Wildcards and truncation Search engines also process some aspects of language differently than we do: Punctuation is usually ignored, though there are exceptions. Capitalization is also generally ignored. Spelling: Humans can still figure out what you mean when you misspell something. Computers can't always, though they're getting better at it. Boolean Operators AND: Only returns pages that contain both terms. AND is generally the default
used when you type a string of terms into a search engine. OR: Returns all pages that have either one of the terms listed. The example at
right isn't very useful, but something like [Scotland vacations OR holidays]
would be a good example of its use, to make sure you get results using both
the American and British words for a vacation. NOT: Specifically excludes a term, which helps when you're looking for a word
that's commonly associated with another. This is often indicated with a minus
sign. In the example to the right, if you wanted to search for just "rock" without
its musical meanings, you might try a search like [rock -roll -music]. This would
return all of the pages with the word "rock" in them and without "roll" or "music". Phrase Search Example Searching for just [George Bush] will give you results for both U.S. Presidents with that name. Searching for ["George Herbert Walker Bush"] should narrow your results to just pages that mention the elder Bush. Even getting more specific with [George Herbert Walker
Bush] won't guarantee your results are specific to the 41st
President, since that query also takes in the 43rd President's
full name. These vary by search engine, and you'll
usually have to check the documentation
to know for sure. Google, for example, lists
their exceptions here: Exceptions to Rules http://www.google.com/support/websearch/bin/answer.py?hl=en&answer=136861 Punctuation in popular terms that have particular meanings, like [ C++ ] or [ C# ] (both are names of programming languages), are not ignored.
The dollar sign ($) is used to indicate prices. [ nikon 400 ] and [ nikon $400 ] will give different results. Wildcard Example You can use an asterisk to replace a letter or letters in a word, and a search engine will look for all variations on it. For example if you wanted to include both "woman" and "women" in a search, you could just use [wom*n]. Truncation is when you do this at the end of a word. For example if you wanted all of "politics" "political" and "politician" you could use [politic*]. This searches for any word that begins with "politic". Many search engines also have special commands called operators that let you
modify or limit your searches in interesting ways. We'll go over some examples
from Google, but check the documentation on whatever engine you are using to
see if it has anything like these. Search Operators Google uses the format [operator: search terms] for its operators. Examples:
[define: word] Will return dictionary definitions for that word.
[tuition site: www.illinois.edu] will search just the U of I website for the term "tuition".
[link: www.illinois.edu ] will return sites that link to the U of I website
[related: www.illinois.edu] will return sites related to the U of I website. There are many more, and some of them work differently. You can find a full list with examples at: http://www.google.com/intl/en/help/features.html Search is Iterative Search is Conceptual Search is Associative Search AS a Strategy Know When to Give Up Think Like a Search Engine Sometimes general search engines like Google just aren't the right tool for the job. If you try several different strategies and still don't find what you need, it's likely time to look elsewhere. We'll give some suggestions for what else you can try if you come up empty later on in this lesson. Remember the things we learned earlier about how search engines work: They index the text directly from documents, and look at things like word
frequency and proximity, common phrases, etc.
They often look at the links between documents and weight results based on
the amounts of incoming links to a document associated with a given keyword.
They "think" rather robotically and literally, and usually don't have much
direct human intervention to make their indexes resemble our ways of
thinking and communicating more closely. Try to "think like a search engine" in the same way you might "think like the
test". Keep the limitations of the software in mind, as well as the criteria it uses. For anything that's not simple and straightforward, you're
going to have to take multiple stabs at it to get the best results. Don't be afraid to choose rather randomly when it comes
to initial keywords. It gives you a place to start, and then you can revise and
refine your search from there based on the results you get. The key is to always keep revison in mind as your default strategy. Good
deep searches will almost always involve some trial and error. Learn to
be critical of your first set of results, and to think of ways they might be
improved. Remember your AND/OR/NOT, wildcards, quotes, and other
tips and tricks for refining your searches. With time, this process will start to become second nature, and you won't
even need to think about it consciously. Break down what you're looking for into discrete, simple concepts.
Whittle down from sentences and paragraphs to words and phrases.
Then think in terms of single keywords, and look for synonyms.
Try to determine what's unique about what you are looking for. Eliminate
everything else from your query.
Again, trial and error will help you home in on the right way to describe
what you're after. Use the search engine and the results it gives you to help
refine your concepts and keywords. Since search engines generally look at what words, phrases, and concepts
are related to one another by either proximity in a document or links between
documents, free-associating is a pretty good way to put yourself in the mode
for search. Just type the first things that come into your mind
when you think of your concept, and keep on
building and revising your query from there.
This can lead you astray if you happen to have
unusual associations for a given concept, but it
works very often and it's a great way to get
unstuck if you're having trouble. These examples actually don't work for Google, which only lets you use wildcards to replace entire words in a phrase. They do work in many other search contexts though. The other strategies have been hinting at this, but if you're really stuck in trying to define your concept, you can actually flip the script and use search AS a strategy to do just that.
Since a general search engine is an association machine fueled by the entire internet, that spits our related items when you put in keywords, often just playing around with different guesses at sets of keywords and results can do a lot to firm up your thinking about what you are looking for, or give you good initial leads on what's related to a given idea or concept. Sometimes it takes a search to define your search. In this section we'll look at a screenshot for the results of a complex Google search, and talk about
the different elements on the page, what they are, and what they do. This link goes to a
timeline that documents
changes in the use of the
search term over time.
If you were to check this,
you'd see that it lines up
neatly with the dates when
the team both moved to
and left St. Louis. These links will run the
same search you just
tried, only limited to the
specific sections of Google
like News or Images. More
on them later as well. I chose this search to give an example of a complicated query that benefits from advanced operators. Since the football and baseball teams share a name, you need the -baseball in there to narrow it down to football-only. Anatomy of an individual Google search result. Keep in mind that these interfaces and results are
the ultimate product of all the processes described above. Try to think about each element you see and how it might have been produced or collected by the crawler or indexer, and how it's presented by the search engine and why. The Google Search Interface Try Advanced Search Other Things to Try Most search engines have an advanced search interface.
It gives you a lot more options for constraining your search, and also guides you through constructing complex queries.
Here's what Google's advanced search looks like. Think about the type of information you're looking for. Is there a specialized search engine that covers it better? Movies and TV shows - IMDB: http://imdb.com
Basics on people, places, and things - Wikipedia: http://wikipedia.org
Government information - FDSys: http://www.gpo.gov/fdsys/
Realtime information on current events - Twitter: http://search.twitter.com
Google's many specialized offerings Google's Specialized Searches Google offers many different sub-search engines that specialize in specific types of content. If you know that what you are looking for fits the type, you're often better off starting with one of these instead of the main Google search.
Images - Go here to find image files.
News - Indexes handpicked news sources. Good and reliable for current events.
Blog Search - Indexes many, but not nearly all, blogs. Good for opinion and pop culture.
Google Books - Indexes the full text of millions of books, and lets you read many of them.
Google Scholar - Indexes and collects citation information on scholarly/academic articles.
Google Maps - Maps + Yellow Pages and other geographic information.
Google Groups - Indexes discussion groups. Good for problem solving and tips.
YouTube - Go here for video files. Online, But Not
Freely Available Online, But Not
Searchable Things Not Online Many sources have been digitized, but are only available in for-pay databases or on subscription-only sites, and thus aren't found by Google or other general web search engines.
Most archives for periodicals and newspapers.
Most scholarly publications
Most books still in copyright.
Many reference books and materials.
Many specialized sources of information, such as statistics, reports, business, legal, and medical information. Many things are online, but not able to be indexed by search engines for various reasons. Some estimates put the total of this content at many times the amount of searchable content.
Some non-html or text file formats, though this is improving.
Some database-driven websites that crawlers can't parse.
Much of the social web and other password-protected content, like Facebook.
Pages that don't have links in or out. The crawler has to follow a link to find a page.
Sites that explicitly exclude search engine crawlers. Digitization has come a long way quickly, but nowhere near all of human information and culture has made its way online.
Millions of books and periodicals either too obscure to justify the costs of digitization or of uncertain copyright status.
The vast majority of commerical film and TV ever created, and the vast majority of photography as well.
Much if not most local historical and government information, and other such scattered archives and data collections.
Millions of other sources and documents, both public and private. Social media, blogs, listservs, and communities of practice. Find out where the conversations about your topic of interest are happening online, and join in.
Ask an expert sites. Lots of sites let you ask a question to a community of knowledgeable people. These are especially good for tech issues or local knowledge. Example: http://ask.metafilter.com
Print sources. Don't forget your library, your local historical society or museum, and your county courthouse.
Ask a librarian! We're experts at finding and evaluating information, and we can help you find what you need. Information Literacy Lesson 2 Basic Search