| Data source |
Advantages |
Disadvantages |
| Crossref |
- No need for a subscription key
- Usually provides cleaner and smaller number of irrelevant results than Google Scholar and Microsoft Academic
- Good data source for “any of the words” keyword searches and journal searches by ISSN
- Search speed fast to medium
|
- Typically reports fewer citations than Google Scholar and Microsoft Academic, because it includes fewer journals in some fields and has very limited coverage of books, book chapters and conference papers
- The use of NOT or AND in keyword searches results is ignored; Crossref reverts to OR searches
- Author search is problematic as it is very difficult to disambiguate authors
- Year of publication is sometimes - but not always - year of online-first, not year of print publication
|
| Google Scholar (GS) |
- No need for a subscription key
- "Forgiving" search syntax
- Usually provides the largest number of publications and citations
- Search speed medium for single search with limited number of results
|
- Usually provides a larger number of irrelevant results than other data sources
- Author disambiguation more difficult than GSP, MA and WoS
- Because of necessary search rate limitation, speed slows down considerably when doing multiple searches in quick succession or running searches with many results
- Year of publication is sometimes - but not always - year of online first, not year of print publication
|
| Google Scholar Profile (GSP) |
- No need for a subscription key
- Most "forgiving" search syntax
- Very quick search, 1-3 seconds for most authors
- Manual curation by the academic usually means cleaner results than GS
|
- Only available if academic in question has set up a profile
- Can contain "dirty data" if academic has not curated their profile
- Can be consciously manipulated by unscrupulous academics by adding papers not written by the academic themselves
|
| Microsoft Academic (MA) |
- Usually provides a smaller number of irrelevant results than GS
- Search speed very fast for searches with less than 200 results, but fast even for repeated searches and searches with many results
- Usually provides cleaner results than GSP as not all user curate their GSP
- Seems to provide best automated author disambiguation
|
- More restrictive search syntax
- The use of NOT in keyword searches results in an error message
- Because MA favours semantic over lexical searches, it results in an error message if you include stop words such as "the", "a", "from", but also common academic words such as study and method.
- Year of publication is usually year of online first, not year of print publication
- Requires a (free) Microsoft subscription key
|
| PubMed |
- No need for subscription key
- Provides a maximum of 1000 results for journal and keyword searches; higher maximum with free NCBI API key
- Includes abstracts in results
|
- Specialized data source for biomedical subjects only
- Only provides a maximum of 199 results for author and affiliation searches
- Does NOT include citations; hence citation metrics cannot be calculated
|
| Scopus |
- Provides cleaner and smaller number of irrelevant results than Google Scholar and Microsoft Academic
- Typically reports more citations than Web of Science
- Very good data source for keyword searches and journal searches by ISSN
|
- Requires a free API key from Elsevier for basic results
- Full results require (non-free) subscription
- Search speed slow, but still acceptable
- Typically reports fewer citations than Google Scholar and Microsoft Academic, because it includes fewer journals in some fields and has a limited coverage of books, book chapters and conference papers
|
| Semantic Scholar |
(to be documented; currently the Semantic Scholar API is very limited) |
| Web of Science |
- Provides cleaner and smaller number of irrelevant results than Google Scholar and Microsoft Academic
- Search speed very fast for nearly any kind of searches
- Allows wildcards (e.g. global*) for easier searches
- Very good data source for keyword searches and journal searches by ISSN
|
- Requires (non-free) subscription
- Typically reports fewer citations than all other sources because it includes fewer journals in many fields (esp. Social Sciences and Humanities) and has a very limited coverage of books, book chapters and conference papers.
- Typically is last data source to include recent publications as it doesn’t include “in press” papers.
|
Anne-Wil Harzing is Professor of International Management at Middlesex University, London and visiting professor of International Management at Tilburg University. She is a Fellow of the Academy of International Business, a select group of distinguished AIB members who are recognized for their outstanding contributions to the scholarly development of the field of international business. In addition to her academic duties, she also maintains the Journal Quality List and is the driving force behind the popular Publish or Perish software program.