As Wikipedia has become one of the most used knowledge bases worldwide, the problem of the trustworthiness of the information it disseminates becomes central. With WikipediaViz, we introduce five visual indicators integrated to the Wikipedia layout that can keep casual Wikipedia readers aware of important meta- information about the articles they read. The design of WikipediaViz was inspired by two participatory design sessions with expert Wikipedia writers and sociologists who explained the clues they used to quickly assess the trustworthiness of articles. According to these results, we propose five metrics for Maturity and Quality assessment of Wikipedia articles and their accompanying visualizations to provide the readers with important clues about the editing process at a glance. We also report and discuss about the results of the user studies we conducted. Two preliminary pilot studies show that all our subjects trust Wikipedia articles almost blindly. With the third study, we show that WikipediaViz significantly reduces the time required to assess the quality of articles while maintaining a good accuracy.