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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