One Entry to Research: critical assessment of Web of Science(WoS),

Scopus and Google Scholar(GS)

10.50-11.10 Friday 15 Sept

EAHIL 10th conference 2006 in Cluj-Napoca, Romania

Speaker:Lars Iselid

BIBSAM-project from 1/1 2006 – 31/8 2006:One Entry to Research – critical assessment of Web of Science, Scopus och Google Scholar

oneentry.wordpress.com

Primarily evaluations of multidisciplinary citation databases

Citation search Author search Address and department/institution search

Subject search and coverage

Overlap and coverage between Scopus, WoS etc (Not GS)

Questions for the libraries?

Shall we keep Web of Science or supplement with or change to Scopus?

Or do we need them at all when we have Google Scholar for free?

Is it sufficient to search for citations in Web of Science or should we also consider Scopus and Google Scholar?

Are these databases fullworthy as subject databases?

Answers from a librarian!

No, we should not use Google Scholar exclusively, which has lots of flaws for both citation and subject search.

If we want to find more cited references concerning research from 1996 and present we have to consider Scopus (and Google Scholar even pre-1996) beside of Web of Science.

Google Scholar has often unique citations in comparision with Scopus and Web of Science.

Rantapaa*

8 name variants

Rantapaa S*

2 additional name variants

Of course much of the incorrect author spellings in Cited Ref Search could be blamed on incorrect citation information from article authors.

The Lancet-article?Rantapaa Dahlqvist or Rantapaa-Dahlqvist

The Lancet-article?Rantapaadahlqvist

The Lancet-article? Rantapaa-Dahlquist

The Lancet article!

Original e-journal article

Lancet article in

Rantapaa* S

Lancet article in

Dahlqvist, S.R.

Lancet article in

Bad implementation of data!Address is missing for Rantapää

…but in the original e-journal article, it’s there!

Search with limit umea could produce false amount of citations!!S Astrom umea

S Astrom Dept ophthalmol

Eriksson s* umea

S Eriksson Umea plant sci ctr

S Eriksson Geriatr Ctr

Staffan Eriksson at the same department published as S Eriksson

Lots of flaws when counting citations in Google Scholar. Many duplicates! Has no address field.

Why all these errors?

Lacking (raw)data from the beginning.

Unsuccessful indexing of (raw)data from the vendors Elsevier, Thomson och Google.

Algorithms can’t solve lacking (raw)data, perhaps tune up some errors.

It’s not a question about algo’s, it’s a question about structured well-indexed data.

Coverage evaluation of WoS and Scopusaccomplished by Ylva Gavel, KIB, och Lars Iselid, Umeå UB.

We’ve been matching ISSN against Ulrich’s journal database to exclude non-active titles, obsolete/invalid ISSN, titles not covered. It’s remarkably many.

Study will be published in a scientific journal if accepted.

Coverage evaluation of WoS and Scopus - How many active titles?

Scopus 13.226 journals

WoS8.786 journals

Coverage evaluation of WoS and Scopus - How many active titles overlap and how many are unique?

WoSScopus

7.210 indexed both inScopus andWoS

All together14.802 journals with unique ISSN.

Coverage evaluation of WoS and Scopus - How many active titles overlap?

WoS covers55% of Scopus

Scopuscovers 82%of WoS

49 %existin both

Active titles in each database

0

2000

4000

6000

8000

10000

12000

14000

Active titles

Soca 1.870

PsycINFO 1.972

Compendex 3.890

Medline 4.843

Embase 4.763

Web of Science 8.786

Scopus 13.226

Average overlap of WoS 51,8%

Scopus

WoS

Medline

Embase

Compendex

PsycINFO

SociologicalAbstracts

55%

55%

46% 57%

36%

62%

Average overlap of Scopus 74,2%

Scopus

WoS

Medline

Embase

Compendex

PsycINFO

SociologicalAbstracts

82%

91%

45%

71%

67%

89%