2.3 Limitations

Based upon the examples, the technical basis and our experience as librarians, we have identified the following limitations you have to take into account while working with VOSviewer:

- Large dataset needed for most evaluations (at least 100-200 items) => alleen tot zijn recht als je een grotere set hebt, anders statistisch niet relevant

- The parameters and dataset you provide determine what the visualization will look like. It is important to know that the software can be used mainly for qualitative indications and not so much for quantitative measurement. It is also necessary to be very specific while working with VOSviewer:

o How did I obtain my data (search query, database, date, number of results)

o What parameters did I use to create my maps (counting method, excluded keywords, number of occurrences/citations, etc.)

o Did I change visualization parameters?

o Write down what you see in the different clusters and what this tells you

o Why did I make these choices?

o It may be difficult to assess if you are not an expert in the field yet. Always ask an expert (supervisor for a Ph.D. for example) to have a look at the map and help with the analysis. In my experience they immediately see patterns and are usually quite surprised by the results.

o The software is not automatically updated; check the VOSviewer website regularly as new functionality is rolled out frequently.

o Non-standard databases/materials without DOI need additional work to be used.

o Author analysis: the authors are defined by name, not by Orcid. This means it is unusable in fields dominated by Chinese authors.

o Term extraction is based on English language/grammar. The algorithm used for natural language processing is not suitable for other languages. In the examples we will explain how to convert text to English.

Be aware that using VOSviewer is an iterative process. Most likely your first tries will give you some information to improve your search or visualization.