What is webometrics?

Webometrics is (a) a set of quantitative techniques for tracking and evaluating the impact of web sites and online ideas and (b) the information science research field that developed these ideas. Webometric techniques include link analysis, web mention analysis, blog analysis and search engine evaluation, but from the perspective of digital library evaluation the main method is link analysis.

Why can analysing web hyperlinks help evaluate digital repositories? The reason is that the links to a web site can reveal useful information about how popular it is, which pages or resources are the most popular, why it is popular and where it is popular. Whilst all this information can also be gained from web server log file analysis, the latter can normally only be conducted with permission of a site’s webmaster. In contrast, link analysis can be applied to any web site. This means that link analysis can be used to evaluate a web site by comparing it to its competitors or to similar web sites and can also be used to identify missed audiences for a site.

Links can reveal information about web sites because each link to a web site may be created to direct visitors to it.  The link author believes that the target site is important or useful. For example, the course pages for an archaeology degree may contact links to the New Library of Alexandria for its images of ancient Egyptian artefacts. From the opposite perspective, discovering all the links to the New Library of Alexandria web site would give useful insights into who was using it and why. Of course, most people using a web site will not create a link to it but a link analysis can still give indicators about likely users and uses.

Links can reveal information about where a web site is used because many links originate from web sites with a top-level domain that identifies their geographic origin (e.g., .uk for UK, .es for Spain). Links can also reveal why a web site is used through reading the web pages hosting the links.