How to Search for Evidence Online in Dentistry

If you steal from one author, it's
plagiarism; if you steal from many,
it's research.
INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com

SEARCHING FOR EVIDENCE
Dr R. V. SUBRAMANYAM
Professor & Head, Oral Pathology
Director, CODS-EBD
College of Dental Sciences, Davangere 577 004

WHERE TO SEARCH?
Colleagues
Books
Journals
Newspapers
The INTERNET

THE WORLD OF INTERNET

WHAT IS INTERNET?
 World’s largest dictionary
 Network of networks
 Community of people who
use and develop those
networks
 Collection of resources that
can be reached from those
networks

 Hypertext: Documents that
contain links to other
documents.
 HTTP: Hypertext
Transmission Protocol.
 HTML: HyperText Markup
Language.
 XML: Extended Markup
language
 DHTML: Dynamic HTML
TERMS

TERMS
URL: Uniform Resource Locator
com: For commerical
organizations, businesses.
edu: Educational organizations,
universities, secondary schools.
gov: Governmental
organizations, non-military.
mil: Military, Army, Navy.
org: Other organizations.
net: Network resources.

WHAT IS A BROWSER?
Software that helps you to surf the net for
information.
Internet Explorer
Netscape Navigator
Opera
NCSA Mosaic
WHAT IS A SEARCH ENGINE?
Free online resources that help in hunting
for information. Not same as DIRECTORY.

DIRECTORIES
General information.
A short description has to be submitted to the
directory for your entire site, or editors write one
for sites they review.
A search looks for matches only in the
descriptions submitted.
Eg: Yahoo! (http://www.yahoo.com)
Hotbot (www.hotbot.com)

SEARCH ENGINES
 Create their listings automatically.
 Search engines crawl the web, then people
search through what they have found.
 If you change your web pages, search engines
eventually find these changes.
 Eg: Directhit (http://www.direct.hit.com)
 Hybrid Search Engines: Some search engines
maintain an associated directory.

WHAT IS A METASEARCH ENGINE?
 Submits your query to multiple search
engines with combined list of results.
Ask Jeeves (http://www.ask.com/)
Mamma (http://www.mamma.com/)
Metacrawler (http://www.metacrawler.com/)
 More information about search engines
on:
http://www.searchenginewatch.com/

WHY USE A SEARCH ENGINE?
There are an estimated 900 million
documents on the Internet.
The inability to find the
information is frustrating.
More than 2,500 search services
presently on the Web.
Internet is so big, so powerful and
pointless that for some people it is a
complete substitute for life.
Andrew Brown

Search Styles
ANTS: The carefully planned,
methodical search hoping to get
exact results on the first try.
GRASSHOPPERS: Intuitively
jumping from topic to topic,
refining results as more is
learned.

SEARCH SITES
 AltaVista [http://www.altavista.com/]
 About.com [http://www.about.com/]
 Ask Jeeves [http://www.askjeeves.com/]
 Direct Hit [http://www.directhit.com/]
 Excite [http://www.excite.com/]
 Go [http://www.go.com/]
 Google [http://www.google.com/]
 HotBot [http://www.hotbot.com/]
 Infoseek [http://www.infoseek.com/]
 Lycos [http://www.lycos.com/]
 WebCrawler [http://www.webcrawler.com/]
 Yahoo [http://www.yahoo.com/]

SEARCHING FOR HEALTH
INFORMATION

Searching for Health Information
 Health Search Sites
 Boolean Basics
 MeSH and MeSH Browser
 Search terms
 Electronic sources of clinical evidence

Search Sites for Health
 PubMed: http://ncbi.nlm.nih.gov/PubMed
 Medportal: www.medportal.com/
 Dentalgate: www.dentalgate.com
 CLINIWEB: www.ohsu.edu/cliniweb
 DR. FELIX: www.docnet.org.uk/drfelix
 HEALTHGATE : www.healthgate.com
 Healthworks: www.healthworks.co.uk/
 MEDFINDER: www.netmedicine.com/
 OMNI: www.omni.ac.uk/
 TRIP: www.gwent.nhs.gov.uk/trip/

BOOLEAN BASICS OF SEARCHING
Boolean logic is used to construct search
statements using logical operators and
specified syntax. These are combined into
Boolean expressions, which always are
either true or false when evaluated.
List of operators and syntax available to
Boolean searching:
 AND
 OR
 AND NOT
 BEFORE
 AFTER

AND
Means "I want only documents that contain
both words.“
Focuses, coordinates and narrows a search.
It operates on the terms or phrases on both
sides of it.
Example: recurrent AND aphthous
recurrent aphthous

OR
Means "I want documents that contain either
word; I don't care which word.“
Broadens a search and makes it less
focused.
Example: recurrent OR aphthous
recurrent aphthous

MeSH and MeSH Browser
MeSH: Medical Subject Headings.
The MeSH Browser is an online vocabulary
look-up aid available for use with MeSH.

MeSH Applications
Effective selection: Items of interest may
be readily found.
Indexing articles for the MEDLINE
database and for other NLM-produced
databases.

SEARCH TERMS
ab words in abstract
pt Publication type
ti words in title
tw text words
 / MeSH subject heading
 $ truncation (words from single stem) (?)
 jn Journal
au author
 * major focus of the article

PITFALLS TO AVOID
Avoid Misspellings
Hamartoma and haematoma
Redundant Terms
anemia and blood disorder
Ignored Terms and Special Characters
~ ! @ # $ % ^ & ( ) = | { } ' " < > ? / , . _
Alternate Spellings
ANEMIA, ANAEMIA

How to Get the Right Stuff and Avoid
Getting the Wrong Stuff!
 Specificity Likelihood of excluding
irrelevant items.
 Sensitivity Likelihood of retrieving
relevant items.

If you're doing a search and it yields an
unmanageably large number of hits, you
probably need to increase the specificity
of your search.
Conversely, if you get too small a number
of hits, you probably need to increase
sensitivity.
How to Get the Right Stuff and Avoid
Getting the Wrong Stuff!

SENSITIVE SEARCH
SPECIFIC RESULT
SPECIFIC SEARCH

Increase specificity by:
 Narrowing your question!
 Using more specific terms.
 Selecting specific subheadings with MeSH
headings
 Limiting to language of article, to human or
animal subjects, to publication types (e.g.
randomised controlled trials, reviews, etc.), to
country or year of publication

Increase sensitivity by
 Broadening your question!
 Finding more search terms from relevant
records.
 Trying different combinations of terms.
 Adding in and combining terms of related
meaning using OR, ? etc.
 Selecting All Subheadings with
Thesaurus/Subject MeSh terms.
 Searching further back in time.

Electronic sources of Clinical Evidence
The Cochrane Library: CD –based source of
resources which is updated quarterly.
Best Evidence: CD-based Newsletter/ Journal
Critically Appraised Topics (CATs): Critical
appraisal of evidence tracked down to answer
specific questions.

OTHER SOURCES OF EVIDENCE
 Silverplatter
 Ovid

Murphy’s Law on Search Engines
No matter how precise or accurate the
query, a large percentage of results returned
by search services WILL NOT BE WHAT
YOU'RE LOOKING FOR !
THANK YOU

How to Search for Evidence Online in Dentistry

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