Why Does the H-Index Differ Between Databases?
H-index is treated in a report from the Department for Publication Infrastructure. The possibilities to calculate the indicator for the KTH researchers as well as differences between databases for calculating the h-index is treated in the report. The indicator and its characteristics is also described.
So why does the h-index differ between databases? Well, different databases (Web and Science, Scopus and Google Scholar) cover different publication quantities. This means that the total possible number of citations differs between the databases. The quality of data also differ because the databases are indexed in various ways, Scopus and Web of Science use manual indexing, while Google Scholar collects and indexes the material automatically. A higher number of publications and, consequently, more possible citations does not necessarily mean a better database, it can also bring about poor data quality and lower requirements on the indexed material.
Read more about the h-index in the report