3. Knowing the limits of Google Scholar

Using Google Scholar presents a number of difficulties and weaknesses, first and foremost the opacity and incompleteness of its corpus.

• Some sources are known (Elsevier, INIST, SUDOC, Ingenta, PubMed, Springer...), but there is no list of indexed titles on the Google Scholar site, nor is there a list of sources (commercial publishers, archive servers...).

• Nor is there any indication of the period covered or the frequency of updates, and therefore of the freshness of the content.

• Also missing is a presentation of the types of scientific documents used and the selection criteria; in fact, it seems that Google Scholar also integrates resources that are not academic, but which have more or less the appearance of scientific articles (author, title, institution, source)....