Pros and Cons
Katharine Jackson
January 2010 (adapted from the 2009
session)
Today
• Google Scholar offers a very convenient method of
retrieving article citations and often the accompanying full
text, and is growing in popularity. This session offers tips on
using it effectively and extending your search to other
sources should Scholar's coverage prove inadequate for
your purposes.
• The World Wide Web – how useful is it?
• Coverage of Google Scholar (GS)
• Using Google Scholar to find academic material
• How to get the most out of Google Scholar
• Pros and Cons in comparison to other sources
Welcome to the Web
The Internet is the world's largest library. It's just
that all the books are on the floor. ~John Allen
Paulos
“Getting
When I took office,
We've heard that a million monkeys at a
million keyboards could produce the
complete works of Shakespeare; now,
thanks to the Internet, we know that is
not true.
Robert Wilensky
information off
the Internet is
like taking a
drink from a fire
hydrant.”
Mitchell Kapor
The Internet is the most powerful
magnifier of slack ever
invented. ~Author Unknown
only high energy
physicists had ever
heard of what is
called the World
Wide Web.... Now
even my cat has its
own page. ~Bill
Clinton, 1996
The Internet is so big, so
powerful and pointless that for
some people it is a complete
substitute for life. -- ,
freelance journalist
Welcome to the Web
The world’s biggest haystack
Looking for a needle - why start in a
haystack?
Why do people love Google?
•Very fast – it even tells you how fast
•Brings up a large number of results
•Often has a number of ‘relevant’ results
within the first page
•Simple interface
•It’s free
Finding needles – how does Google
do it?
• Google is an index of web pages
• It uses clever algorithms that take into account
links from other pages and click throughs
• BUT Google are very secretive as to exactly how
they do it
So why not use it for journal
articles?...
• Individual articles may not be a web page
• Articles may be behind a firewall and how are you going to
know?
• The sheer amount of results
• Are the top results the ‘best result’?
• How would you index an article?
•
•
•
Read it? Google doesn’t read
Give it controlled index terms? Google doesn’t have a controlled
vocabulary
Be able to see the context? Google is not able to determine
context
So what did Google do….
• Teamed up with publishers so they let them search behind
their firewalls
• Modified the algorithm so it excludes non-scholarly material
(as defined by Google of course)
• Used citations to help relevance
• Included library locations for full-text access (Library Link)
But what did they not do…
• Create controlled vocabularies
• Create standardisation of journal
names/abbreviations
• Give any details of which journals/publishers they
included
• Give any info on how the system decides what is
scholarly
• Give an indication of update frequency
Still not giving any indication on how it
works
NB: only in Beta
• Launched 18 Nov 2004 but still beta - features change
• Developing in tandem with Google Books, which includes
digitised texts from Oxford collections and others
• In competition with WoK, SCOPUS etc
What’s in Google Scholar?
“Google Scholar provides a simple way to broadly
search for scholarly literature. From one place, you
can search across many disciplines and sources:
peer-reviewed papers, theses, books, abstracts and
articles, from academic publishers, professional
societies, preprint repositories, universities and other
scholarly organizations. Google Scholar helps you
identify the most relevant research across the world of
scholarly research.”
Content
• Access to materials locked behind subscription barriers
• Must include abstract
• Full-text access requires institutional subscriptions or
individual payment, unless open-access
• Includes peer-reviewed papers, theses, books, preprints,
abstracts, full-text, citations, etc.
• Includes OpenURL links to local library holdings - “Library
Links”
• In Oxford displays as ‘Oxford Full Text’ beside title
• Includes citation data
BUT no list of publishers that have allowed Google
access or publication list
Searching
• AND implied between words as in normal Google
• + to include common words, letters or numbers that
Google’s search technology generally ignores
• “quote marks” to search for a phrase
• minus sign – to exclude from a search
• OR for either search term
• author: for author search
• intitle: to search document title
• restrict by date and publication
Advanced search screen available
A simple example……
Let’s try
rhinoceros tusks
Context might be
• Ecology
• Law
• Medicine
• Art
etc
Basic search box
Advanced
search
Set up Library Links
through
Preferences
Remember to
save
Can search for
libraries
But if on Oxford
network it
should already
be there
If we scroll further down the preferences page…
we can set up
preferences to
show links to
import
citations into
different
referencing
software
Basic search box
Advanced
search
Set up Library Links
through
Preferences
Has citation
information, related
articles and a link
through to different
versions
Shows where the
item is a book
rather than an
article
Links through to
location in Oxford
If we scroll down the page….
Includes citations
Search tips to use
Advanced search
Ability to
narrow
search for
specific
publications,
dates or
authors
Narrow down by
subject
How does it compare to Web of
Knowledge and Scopus?
Web of Knowledge
“One platform for access to objective content and powerful
tools that let you search, track, measure and collaborate in
the sciences, social sciences, arts, and humanities.” Web
of Knowledge website
Scopus
“Scopus is the largest abstract and citation database of
peer-reviewed literature and quality web sources with
smart tools to track, analyze and visualize research”
Scopus website
Can select a subject based
database
No way of searching full
text
But can search for
specific authors and
journals
This search only brings up one
result!
Searching for a specific item..
“Mood state effects of chocolate”, G Parker, I Parker, H
Brothie, Journal of Affective Disorders, 92, pg149-159
This time choose
‘Advanced
search’
Can use the
title in the
exact phrase
box
Link through to
Oxford
holdings
Link through to a list of
articles citing this
article
Can use the ‘title’ and ‘author’ field
Allows you to
refine your
search from
this page
Also links
through to full
text and has
the number of
times cited as
15
Have to click
on ‘add
search
field to be
able to put
the author
in
Has link through to
a list of 19
articles
Link to see
where it is
in Oxford
Link to full text
Differences in Citations
• GS had 21 articles citing, WOK had 15 and Scopus had 19.
• Google had 10 out of the 19 items that were listed on
Scopus and 9 out of the 15 that were listed on WOK.
• GS had 8 ‘unique’ items that were not on WOK or Scopus.
WOK had 1 unique item and Scopus had 4.
Differences in citations
• GS uses citation extraction to build links between articles
• Already seen in all the databases the ‘cited by’ links which
link through to articles that have cited the results
But
• As different databases have different literature sets the
numbers will be different
• With GS the most cited articles will be at the top of the
results list (which hopefully means the most authorative)
but not always the case.
• GS also includes non scholarly material as well as books
Pros and Cons of Google Scholar
Peter Jacso reviewed Google Scholar in 2005 and then
revisited it in 2008 in his article “Savvy Searching: Google
Scholar Revisted, Online Information Review, 32, no 1
2008,pg 102. This looked at over 100 papers on Google
Scholar.
Pros
• Content has grown since GS started and now GS indexes
Elsevier and American Chemical Society.
• The Google books project has significantly enhanced the
content.
• Has started to include content for languages other than
English
• Has indexed records where no digital full text is available
and so can point the researcher to the primary source via
document delivery
• Library Links is extremely good at identifying sources
locally.
Cons
• Although the content has grown there are still significant
gaps in the top ranking journals.
• Its search operations has serious flaws for example in the
filtering of searches by broad subject or publication year
• No official list of what GS actually searches and so no
realistic idea of how many records are included.
• Coverage seems to be sporadic for example Jacso found
that only ¼ of items on Pubmed were available on GS.
• There is no idea of currency
• Some subjects are covered more than others
Further studies…..
On citation analysis
• Harzing, Anne-Wil K. and Ron van der Wal
Google Scholar as a new source for citation analysis
Ethics in science and environmental politics, Vol. 8: 61–73,
2008
http://www.int-res.com/articles/esep2008/8/e008p061.pdf
• Meho and Wang (2007) (on bibliography)
From that article:
• as a general rule of thumb, we would suggest that using
GS might be most beneficial for 3 of the GS categories: (1)
business, administration, finance & economics; (2)
engineering, computer science & mathematics; (3) social
sciences, arts & humanities.
• Although broad comparative searches can be done for
other disciplines, we would not encourage heavy reliance
on GS for individual academics working in other areas
without verifying results with either Scopus or WoS.
and
Meho & Yang (2007) [found] that GS missed 40.4% of the citations found
by the union of WoS and Scopus, suggesting that GS does miss some
important refereed citations. It must also be said though that the union
of WoS and Scopus misses 61.04% of the citations in GS. Further,
Meho & Yang (2007) found that most of the citations uniquely found by
GS are from refereed sources.
The social sciences, arts and humanities, and engineering in particular
seem to benefit from GS’s better coverage of (citations in) books,
conference proceedings and a wider range of journals. The natural and
health sciences are generally well covered in ISI and hence GS might
not provide higher citation counts. In addition, user feedback … seems
to indicate that for some disciplines in the natural and health sciences
GS’s journal coverage is very patchy.
Alternatives to Google Scholar
• Web of Knowledge
• Scopus
• SOLO
• Subject specialised federated searches e.g
PubMed, Scirus for scientific information.
Conclusion
• Maintain a balanced diet!
• Five a day…
•
WoK, Scopus, Intute, subject-specific database,
Google Scholar…
More help
Contact the presenters
[email protected]
Or your subject librarian (listed on
http://www.ouls.ox.ac.uk/libraries/subjects/librarians)
at any time
Bibliography: General Reviews
1. Abram, S, ‘Google Scholar: thin edge of the wedge?’, Information
Outlook, Vol. 9, 44-46.
www.sirsi.com/Pdfs/Company/Abram/StephenAbram_GoogleScholarT
hin Edge.pdf
2. Giustini, D & Barksy, E, ‘A look at Google Scholar, Pubmed, and
Scirus: comparisons and recommendations’, 2005, JCHLA, Vol 26, 8589.
3. Jasco, P ‘Google Scholar revisited’, Online Inf. Rev., 2008, Vol. 32,
102-114. www.emeraldinsight.com/1468-4527.htm
4. Jacsó, P., Google Scholar: the pros and the cons. Online Inf. Rev.,
2005, Vol. 29, 208-214.
5. Vine, R, ‘Google Scholar coverage of a multidisciplinary field’
Information Processing and Management, Vol. 43, 1121-1132
Bibliography: citation analysis
1.Jasco, P, ‘As we may search – comparison of major features of the
Web of Science, Scopus and Google Scholar citation based and
citation enhanced databases’, Current Science, Vol. 89, 1537-1547.
www.ias.ac.in/currsci/nov102005/1537.pdf
2.Yang, K & Meho, L I, ‘Citation analysis: a comparison of Google
Scholar, Scopus and Web of Science’, Proceedings of the 69th Annual
Meeting of the American Society for Information Science and
Technology.
http://eprints.rclis.org/archive/00008121/01/Yang_citation.pdf