Classification of Journal Articles

The classification of about 28 million journal articles has been done using Modularity Optimizer, developed by Ludo Waltman and Jan Nees van Eck at CWTS. The software creates a classification of the publications using direct citation links. The classification consists of four levels of hierarchy, from level 4 with 22 broad classes to level 1 with 35192 classes.

Navigate the classfication by clicking on the labels. Each class contains a list of subclasses, author keywords, journals, words derived from addresses, Web of Science categories, review articles and related classes. This information has been compiled for the purpose to express the subject of each class. Relevance ranking (tfidf) has been used to select the terms in each list. For each class 3 terms with highest relevance score have been used for the label of the class. For the aggregated levels, Web of Science categories usually performes best in the relvance ranking. Author keywords performs best at level 1 to 3.