Facets is a a plotting and visualizaton tool created by the People + AI Research (PAIR) initiative at Google.

Facets is broken into two tools with the following goals:

• Facets Overview – summarize statistics for features collected from datasets
• Facets Dive – explore the relationship between different features in a dataset

From the Facets homepage, they state that

Success stories of (Facets) Dive include the detection of classifier failure, identification of systematic errors, evaluating ground truth and potential new signals for ranking.