Friday, September 02, 2005

Invoked on the Web

The citation analysis is not the only way to analyze the bibliographic characteristics of a paper although it is a key method for bibliometric studies. In a similar way, some proposals intend to restrict the webometric studies to the link analysis and specifically the sitation analysis, the formal links between electronic papers. Obviously, there are many other possibilities to exploit web data, including informal references that can benefited from the large sample size of the webspace.

Cronin et al. (Invoked on the Web. Journal of the American Society for Information Science, 49 (14): 1319-1328) in 1998 proposed to analyse the number of times a researcher’s name appeared cited in web pages. This is equally valid for a title of a paper (introduced formally by Liwen Vaughan and used by Hildrun Kretschmer too, the name of an institution, or selected terms or phrases (You can check some of the papers by Judit Bar-Ilan).

From a methodological point of view, and taking into account that search engines do not cover all the Web and there important bias in their results, invocation can be calculated easily using quotation marks around the name in the search engines. The result is referred as the number of times this name is cited in the Web. Some authors call it Web visibility, although we prefer to reserve this word for link visibility. This indicator usually favours large, well-known, old institutions independently of their real effort for having a relevant Web presence.

Some Peruvian universities were chosen to compare several webometric indicators. Ranked according to the invocation, there are some placements that are not correlated with those obtained with the other indicators.

Although invocation measures can be interesting for some analysis, a cautionary use is recommended as it is not possible to assign a unique, unambiguous universal name for every institution.