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Joseph Harzbecker, MSLS, AHIP |
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Head of Reference Services &
Interlibrary Loan |
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Alumni Medical Library, Boston University
Medical Center |
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617 638-4205, harzbeck@bu.edu |
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Mary McKeon, MSLS |
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Information Services Librarian & Head of
Circulation |
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Alumni Medical Library, Boston University
Medical Center |
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617-638-4253, mamckeon@bu.edu |
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Kathy Schilling, MLS, AHIP |
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Head of Information Management Education |
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Alumni Medical Library, Boston University
Medical Center |
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617-638-4271, kschill@bu.edu |
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Search a variety of search engines efficiently
and effectively, using the engine’s help menus and advanced features |
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Critically evaluate Web sites using quality
indicators and criteria |
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Describe the basic contents and purpose of
MEDLINE |
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Use PubMed to compose simple search questions
and execute simple search strategies |
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The term "search engine" is often used
generically to describe both search engines and Web directories. |
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They are not the same. The difference is how listings are compiled. |
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True search engines |
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Directories |
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Hybrid search engines |
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Meta search engines |
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Created by machines -- “robots” |
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Spider visits a web page, follows links to other
pages (this process is called being "spidered" or "crawled”) |
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Creates a database |
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Your query sifts through the millions of records
in the database to find matches |
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Retrieval is ranked by relevancy |
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A directory such as Yahoo! depends on humans for
its listings |
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Site creators submit descriptions to the
directory for the entire site, or editors write one for sites they review |
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A search looks for matches only in the submitted
descriptions |
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Directories usually have much smaller databases |
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(both engine and directory) |
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These days, almost every search tool is part
engine, part directory |
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Use “spiders” and rely on humans for submissions |
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Do not maintain databases of their own |
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= “middle agents” |
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Transmit your search query to multiple search
engines |
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Results are a compilation of from all engines
queried |
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Saves time in searching multiple engines at-once |
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Provides an overview of “what’s out there” |
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Beware:
avoid complex search strategies |
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Try these meta-search engines: |
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MetaCrawler Inference Find many others |
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Metafind Ask Jeeves |
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A search engine searches the contents of its
database |
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not the Web directly |
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None of these databases includes all the Web
pages in existence, so results vary |
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Each database has different features |
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location of search term |
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Title words are assumed to be most relevant |
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Keywords appearing near the top of a web page
are assumed to be relevant |
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Assumes that any page relevant to the search
term will mention those words right from the beginning |
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frequency of search term |
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Frequency of keywords |
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The result is that no search engine has the
exact same collection (database) of web pages to search |
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Search engines may also give a web page a
relevancy boost if it has a lot of links pointing to it, or if it has been
favorably reviewed |
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Understand what the search engine is actually
doing |
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Recognize that no two engines work exactly alike |
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The more you know about how a search engine
works, the better able you will be to manipulate it to its fullest
advantage |
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Most search engines don’t readily explain what
and how they are searching |
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DO become familiar with one or two favorite
search tools and learn to use their features |
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DO enter singular terms -- many search engines
will find substrings: |
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searching for game will usually retrieve games too |
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DO use collections that have been organized and
quality-filtered by libraries & other organizations |
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Web is highly unstructured and unorganized: |
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No standardized thesaurus or controlled
vocabulary is used |
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Little or no real indexing process occurs |
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No standardization in the types of materials
that are mounted on the Web |
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Criterion #1:
Content |
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Accuracy |
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Disclaimer |
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Completeness |
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Criterion #2:
Credibility |
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Display the name & logo of the institution
responsible for the information |
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Display names of particular authors |
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This information can assist users in assessing
motivations of information providers and potential conflicts of interests. |
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Criterion #3:
Currency |
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Date of the original document |
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Date of posting on the Web |
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This information assists users in judging the
timeliness of the information on the site. |
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Criterion #4:
Site evaluation |
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Sites should indicate whether the information
provided has been subject to review. |
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Site fact-checked or verified in some way? |
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Information accurate and factual? |
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Site sponsored by the agency that produces the
informational content? |
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Criterion #5:
Style & functionality |
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Is the site organized clearly and logically? |
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Is the site well-written? |
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Is the site easy to navigate? |
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Do the links work? |
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Does the site have an internal search engine? |
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The site “architecture” is important for ease of
navigation. |
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Criterion #6:
Purpose, target audience, point-of-view |
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Are the site’s purpose and target audience
clearly stated? |
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Are the site’s point-of-view or agenda clearly
stated or made obvious? |
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The purpose of the site should be clearly
stated, and the information provided should be appropriate to that purpose
or mission. |
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Criterion #7:
Design, software requirements |
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Is special software required to view or
manipulate the site? |
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Does your Web browser alter the appearance of
the page? |
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Look for sites that have a “text only” version
for low-level browsers. |
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Criterion #8:
Disclosure, profiling, confidentiality |
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Is the information you input about yourself
confidential? |
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Does a site “sell” your email address to
advertisers? |
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Does a site require registration? If so, how do you determine what is done
with the information you’ve provided? |
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Criterion #9:
Internal links |
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Do those responsible for the site have the
expertise and credentials to critically evaluate the appropriateness of
links? |
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Are links accurate, current, credible, and
relevant? |
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Criterion #10:
Internal search capabilities |
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Does the site have an internal search engine or
a site map? |
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Is the search engine easy to use? |
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Does the search engine produce realistic, useful
results? |
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An internal search engine with an easy user
interface should be capable of keyword or search string searching. |
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Criterion #11:
Links |
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Those responsible for the site should have the
expertise and credentials to critically evaluate the appropriateness of
links. |
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The content of links should be accurate,
current, credible, relevant. |
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Instability |
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Does a favorite site disappear or move without
notice? |
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Try to determine the stability of a site before
linking to it or becoming reliant on it. |
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Document the URL, producer or location of the
site so that you can locate it later. |
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Site alterations, updates |
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Does a site suddenly change? |
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Is information moved around? |
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Is the site altered without notice? |
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Is the information archived? |
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If this is the case, attempt to verify
information using other sources. |
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“Teasers” & limited free-of-charge access |
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Does a site contain only “teasers” -- leading
you to think the information is comprehensive when it actually is not? |
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Does a formerly “free” site suddenly require a |
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fee-based subscription? |
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Are certain sections or pages of a site
restricted to paying customers only? |
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(Instructors:
Show sample Web sites) |
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Notes