Web scraping (or wrapping) is a popular means for acquiring data from the web. Recent advancements have made scalable wrapper-generation possible and enabled data acquisition processes involving thousands of sources. This makes wrapper analysis and maintenance both needed and challenging as no scalable tools exists that support these tasks.#R##N##R##N#We demonstrate WADaR, a scalable and highly automated tool for joint wrapper and data repair. WADaR uses off-the-shelf entity recognisers to locate target entities in wrapper-generated data. Markov chains are used to determine structural repairs, that are then encoded into suitable repairs for both the data and corresponding wrappers.#R##N##R##N#We show that WADaR is able to increase the quality of wrapper-generated relations between 15% and 60%, and to fully repair the corresponding wrapper without any knowledge of the original website in more than 50% of the cases.
['Stefano Ortona', 'Giorgio Orsi', 'Marcello Buoncristiano', 'Tim Furche']
WADaR: joint wrapper and data repair