"5.3 Delicious Chocolate Chip Cookies
Vizier is also used to solve complex black–box optimization problems arising from physical design or logistical problems. Here we present an example that highlights some additional capabilities of the system: finding the most delicious chocolate chip cookie recipe from a parameterized space of recipes... We provided recipes to contractors responsible for providing desserts for Google employees. The head chefs among the contractors were given discretion to alter parameters if (and only if) they strongly believed it to be necessary, but would carefully note what alterations were made. The cookies were baked, and distributed to the cafes for taste–testing. Cafe goers tasted the cookies and provided feedback via a survey. Survey results were aggregated and the results were sent back to Vizier. The “machine learning cookies” were provided about twice a week over several weeks...
The cookies improved significantly over time; later rounds were extremely well-rated and, in the authors’ opinions, delicious."