Real-world examples of how not to do data
by Rufus Pollock
Bad Data is a site detailing real-world examples of how not to prepare or provide data. It showcases poorly structured, misformatted, or just plain ugly datasets and what they get wrong.
While its primary purpose is to serve as an educational tool for governments and other organizations, it is also a good source of practice material for budding data wranglers—those tasked with cleaning and transforming data. The project began as a place to keep practice data for Data Explorer, another project of Open Knowledge Labs.