Visualizing DOIs classes of errors

Barplot

The barplot helps to compare the values through the difference in length of the associated bars. The values considered were the number of valid citations after the algorithm was run, and the number of citations associated with each considered error class, i.e. cited DOIs containing prefix, suffix and other-type errors. In addition, the bar chart allows comparing the results obtained through this study with those that would have been obtained using the regular expressions suggested in the article Types of DOI errors of cited references in Web of Science with a cleaning method by Xu et al (2019), available at the following address https://doi.org/10.1007/s11192-019-03162-4.

Treemap

The treemap helps to read the data from a hierarchical point of view and to compare the values through area differences. In this case, the root is made up of the set of citations that were corrected by our cleaning procedure. This last category can be further subdivided into citations that contained prefix, suffix or other-type errors that were fixed.