Virtual Testing Environment for Smart Automations in the Internet of Things -- Machine Learning based Finding of Similar Sentences from French Clinical Notes -- A Comparative Study of Energy Domain Ontologies Semantic Label Representations with Lbl2Vec: A Similarity-based Approach for Unsupervised Text Classification Towards Intelligent Processing of Electronic Invoices: The General Framework and Case Study of Short Text Deep Learning in Brazil Indonesia Government and Social Networks: Response Analysis about Food Security during COVID-19 Pandemic An Adaptive Filter for Preference Fine-tuning in Recommender Systems Graph-based Recommendation Engine for Stock Investment Decisions LDViz: A Tool to Assist the Multidimensional Exploration of SPARQL Endpoints Flexible Detection of Similar DOM Elements GeoSoft: A Language for Soft Querying Features within GeoJSON Information Layers.

This book constitutes revised selected papers from the 16th and 17th International Conferences on Web Information Systems and Technologies, WEBIST 2020 and WEBIST 2021, which took place virtually in November 2020 and October 2021, respectively. The 10 full papers from WEBIST 2021 and 1 full paper from WEBIST 2020 presented in this volume were carefully reviewed and selected from originally 48 paper submissions in 2020 and 107 submissions in 2021. The selected papers contribute to the understanding of relevant current research trends in Web information systems and technologies, including deep learning, knowledge representation and reasoning, recommender systems, internet of things, Web intelligence and big data.