<p>RatER Global does not just use the other rankings services. In fact, it is quite biased toward Russian institutions that do not show up in the other rankings. It uses it’s own survey, Google search results, patent volume, etc and the results are typically the most different when compared to the other ones.</p>
<p>HEEACT doesn’t appear to have be updated in some time and their rankings are not generally accessible. (Click on your own link and see) When it has been available, it measures similar outputs as the newer Australian one, which is research output via citation index measures. I would have added HEEACT if I could have actually accessed it over the last couple of days, but it was instead replaced by the Australian RPI ranking. SCImago is another ranking of scientific output (although not restricted to just educational institutions) that could be added, as at least it is accessible. </p>
<p>Webometrics is only a ranking of a university’s presence on the web and is a self-described effort to promote open access. It has nothing to do with overall institutional quality, nor does it claim to be, and represents a single metric: web presence.</p>