Post on 04-Jan-2016
description
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CHBE Orientation ProgramSearching the Literature
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Background
A literature search in the first step in any research program
Recall 551 exam
You need to know What has been done before What techniques have been used Who are the leaders What are the open questions
All of you are now assigned to research groups No better time than the present to start your literature
search By April you will need to present a seminar on your
research topic (requires literature search)
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Objective For Today
Discuss basic strategies for literature searches
Details on Scifinder and web of science, Engineering Village
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Effective Literature Searching
Four key steps Preparing for the search
What information am I looking for? How can I formulate the question so search engine can
answer it Doing the search
Choosing the right initial search terms Choosing the right databases Updating the search terms when you see the results
returned by the databases Be sure to do cited reference searches
Analyzing the results What should I learn from the papers?
Reporting the results Previous literature section of the proposal
Let me get onto Scifinder to Do A Search
http://scifinder.cas.org Need a login: information is at
http://www.library.illinois.edu/chx/sfchanges.html
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Search Engines Are Not People
Search engines use algorithms to find information The cannot understand the scientific content
or importance of an article They can only look for words, phrases,
possibly chemical structures Most search engines are indexed by index
terms and author supplied titles, keywords, references and possibly abstracts
You need to formulate your search so the search engine can find it
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Examples Of Why Indexing Is Important
How can I find this article?
Possible search terms
Polyelectrolyte brushes
METAC Poly 2-(meth
acryloyloxy) ethyl trimethyl ammonium chloride
The structure of the polymer
Reference found
Reference not found
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Example: Something Masel Worked On A Few Years Ago
Polyelectrolyte brushes and related structures as catalyst inks (i.e. polymer supports) for fuel cells
What search terms do I use to find previous literature? Polyelectrolyte brush & fuel cell (no hits) Polyelectrolyte brush (409 references) Polyelectrolyte & brush (609 references)
Several mention nanoparticles Polyelectrolyte & brush & Nanoparticle (50
references – several on target). Am I done?
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At This point I have missed most of the previous literature
Fuel Cell & Nafion – 3986 references Fuel cell & acrylic acid 932
references Fuel cell & styrene sulfonate (300
references)
Am I done?
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Not done yet!!
Only looked at polyelectrolyte’s Also need to search other terms
Catalyst inks for fuel cells
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Key Conclusions
Start with pretty generic search terms Refine terms to find what you want
Do this several times with different key words It is too easy to miss things if you only start with
one group of key words Missing a body of literature guarantees you will
not be funded.
It is better to have more references than fewer
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I find It Is Important To Prepare For The Search
Make a list of keywords before you start
Make sure you cover everything on your list
People tend to stop when they find the first 20-50 interesting references
Having a list keeps me going so I can find the complete literature.
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So Far Only Key Word Searches- Also Need To Do Author
Searches Author searches are much more effective
than keyword searches The search engines do not have to add index
terms I usually find people who are working in
an area and then do author searches I find that I find many more articles this way
instead of using key word and structure searches
Can save search with your competitors names so you always get them
This also gives you ideas for key words
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Cited Reference Searches Much More Effective Than Key Word
SearchesCited reference searches are searches
where you find papers who cited a key paper Indexing cited references can be done
automatically since the author has provided the references in a standard format
Search engine does not have to manually add key words
Not dependent on authors choosing the same key words as you
Much quicker and more effective than key word searches
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Cited Reference Search
Find Papers By Leaders In An Area Find Who Cites those papers Repeat for review articles
Example Masel’s formic acid fuel cell paper from
2002 Kenis work on Laminar Flow reactors
Caution Search Engines Miss Things
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Comparison of SciFinder Scholar and Web of Science Coverage, Whitley, Katherine M. 2002. Analysis of SciFinder Scholar and Web of Science Citation
Searches. J Am Soc Info Technol 53(14): 1210-1215. , doi: 10.1002/asi.10192
Total Citations
Scifinder Citations
Web of Science Cites
Cites in Scifinder but not WOS
Cites in WOS but not Scifinder
3894 3234 2913 981 661
83% 75% 25% 17%
Duplication analysis, haphazard sample of U.S. academic chemistry researchers. (The table shows results for 2-3 researchers in each of seven chemistry subject areas; the chart below shows just the totals / averages of the seven subjects.)
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Search Engines Of Interest
Scifinder Beilstein & Gmellin
Scopus Engineering Village
Web Of Science
Strength Molecular structure + text searches
Information checkedMost complete molecule search tools
Best Search ToolsBest patent coverage
Best for conference proceedingsGreat search tools
CompletenessCited Reference Search
Coverage Chem literature
Chem literature
Leading journals
Engineering literature
All Literature
Completeness
Claims all since 1980, some before
Most since 1771
Most since 1996 some older
Many since 1800
Most since 1980
Conference proceedings
ACS only No Many Many No
Structure search
Good Good No No No
Logical search (and or not)
minimal Some Best Great Yes
Cited ref search
Yes No Yes – but incomplete
no yes
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Scifinder Scholar
Software from Chem Abstracts UIUC has a site license Available on the web http://scifinder.cas.org Need a login: information is at
http://www.library.illinois.edu/chx/sfchanges.html
Need Illinois domain to use Need VPN if you want to use this from home VPN downloadable from
http://www.cites.uiuc.edu/vpn/index.html
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Key Limitations Of Scifinder
Librarians/linguists not chemists do most indexing
Indexing by CAS number not IUPAC structure
Misses articles not published in chemical journals e.g. IEEE sensors, MRI imaging
Patent coverage spotty Logical searches particularly weak
You can and two searches on your computer, but only after you download them 100 references at a time
Weird license limitations
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License Limitations For Scifinder
Download at most 100 references at a time, 5000 per session Requires downloads to do logical (And/or)
searching Allowed to only keep 5000 search
results at a time in format written by scifinder No limitation on references imported to
endnote or refworks provided search results deleted from your computer
No commercial/consulting use
Examples
Scifinder http://scifinder.cas.orgWeb Of Science http://www.library.uiuc.edu/orr/get.php?
instid=258127Engineering Village http://www.engineeringvillage.comScopus http://www.scopus.comGoogle
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Summary
You need a good literature review for orals Start now
Random use of search engines usually misses key literature so you need a strategy
Plan and then execute Be sure to do author and cited reference searches
Strategy should consider indexing – requires a different strategy for
Papers in the last 6 months (usually only cited reference searches)
Papers since 2001 – usually found in common search engines by many key words, structures
Papers before 2001 – only key word and cited reference searches effective.
Cited reference searches are particularly effective since the indexing terms are provided by the authors in a consistent way