Google Scholar
According to Google Scholar, results are ranked by weighing factors such as the full text of a document, where it was published, who authored it, and how often and how recently it has been cited. At first glance, this mirrors how researchers might assess relevance. Yet, Google Scholar does not disclose how these criteria are applied or prioritized.
We may understand why citations play a major role in its ranking system, but research has shown another significant bias. Google Scholar consistently favors English-language publications, even when highly cited non-English works are available. A study using keywords spelled the same in English and Spanish (e.g., capital, invisible) found that in searches of the first 1,000 results, over 900 were in English (Rovira et al. 2021, 17).
VU Library online catalogue
The VU Library catalogue is an important starting point for finding literature. Students can log in with their VUnetID to access ebooks, journals, or request physical books.
Although a library catalogue may seem neutral, results are ranked to prioritize materials available at the VU or accessible through its licenses. This also applies in the default libraries worldwide mode, which technically searches across WorldCat. On the one hand, this is practical, since publications students can access immediately are highlighted. On the other hand, relevant sources elsewhere may remain hidden. The VU catalogue reflects the research and teaching that has historically been carried out at the VU, so that certain niche or emerging topics may be underrepresented. If your students want to embark on such a topic for their paper or thesis, they may miss important literature beyond the VU's holdings if they rely on a quick search.