Accuracy of the results

The citation analysis is based on the results returned by Google Scholar. These are not always 100% accurate. Here are some issues to be aware of.

Note: See More about citation analysis for an in-depth discussion of the validity, assumptions, and limitations of the underlying sources and methods used by Publish or Perish.

Duplicate results

Occasionally you might notice duplicate or near-duplicate articles in the Results list. These duplicates may be due to one or more of the following:

• Sloppy referencing. Not all references to an author's work are perfectly accurate and small differences in the names of the authors, the article's title, or its sources may cause the same article to appear more than once.
• Other funnies. Google Scholar occasionally appears to return duplicate citations or just different results for the same query. This seems to happen particularly when the name you are looking for appears both as a given name and a surname in the returned results, for example Martin, Neal, Tania. If this happens, a second Lookup (with the same parameters) may return more accurate results.

The effect on the citation analysis is that:

• The total number of articles may come out higher than the actual number, because duplicates are counted separately.
• The citations per paper may come out lower, for the same reason.
• The h-index and g-index may come out differently, because citations are spread over the duplicates.

Subject area classification

Google's subject classification is not always spot-on. It pays to experiment a little with the Subject areas boxes that you check to avoid missing citations. If in doubt, leave all boxes checked; this will return all articles, whether classified or not.

Some examples of misclassifications:

• The following journals are classified under Social Sciences rather than Business: Journal of Management, The International Journal of Cross-cultural Management.
• The J Appl Psychol (i.e., the Journal of Applied Psychology) is sometimes classified under Business, sometimes under Social Sciences, and sometimes even under Medicine.
• Some articles appear not to be classified at all. For instance, a search for the article Sources of support and expatriate performance by ML Kraimer et al. succeeds if all Subject areas boxes are checked, but fails for any individual subject area.

These errors and omissions appear to occur fairly rarely, so most searches will be reasonably accurate. However, if they do occur, their effect on the citation analysis is that:

• Some articles may be omitted from the results, because they were classified in an unexpected subject area that wasn't included in the search, or weren't classified at all.
• The total number of articles and other statistics may be underestimated for that reason.

Mixed-up title and source fields

Some references contain mixed-up fields as illustrated in the second reference below:

This is typically caused by garbled information returned by Google Scholar, presumably because its sources were inaccurate or difficult to parse automatically by Google's web crawler.

The effect on the citation analysis is similar to having duplicates (see above), because some works end up as separate entries instead of being included with the correct title.