Editorial of Special Issue of WISE 2019

We are pleased to present a special issue of Data Science and Engineering (DSE), which contains a collection of five papers from the WISE 2019 conference, and two regular submission papers.The International Conference on Web Information Systems Engineering (WISE) has established itself as a community aiming at high-quality research and offering the ground for advancing efforts in topics related to Web information systems.WISE 2019 focuses on research, development, and applications in relation to Web information systems, including a wide range of topics, such as blockchain, deep learning, machine learning, recommender systems, data mining, Web-based applications, graph learning, knowledge graphs, graph mining, text mining, and crowdsourcing.WISE 2019 was held in Hong Kong, China, during January 19-21, 2020.WISE 2019 attracted a total of 211 research paper submissions.The conference program committee selected 50 full research papers (with an acceptance rate of 23.7%), five demonstration papers, and three tutorial papers to be presented at the conference and published in the proceedings [1,2].The conference program also included keynote presentations by