Erratum
The paper titled "Comparison of Four Algorithms for Online Clustering" authored by Xinchun Yang and Wassim Kabbara with DOI : 10.5121/csit.2018.81501" has been retracted due to publication ethics. Prof. HAMDAN Hani, CentraleSupelec, Universite Paris-Saclay claims ownership of this article. He proposed and supervised two of his students, for which they do not have a permission or a right for publication, and whose intellectual property does not belong to them.