The Experiment was an independent publisher launched in 2008. Since 2011 they have been an imprint of Workman Publishing. They publish a range of nonfiction, focusing on practical things such as food (one of the bestsellers they have published is the Forks over Knives Cookbook), health and fitness, psychology and personal development, parenting, relationships, sexuality, and nature. They say “We’re called The Experiment because every book is a test of new ideas—and because we’re motivated by the same curiosity and wonder that drive every scientific experiment. Our books enlighten, empower, and entertain readers with new or freshly presented ideas.”
They publish both narrative and practically oriented nonfiction. They preferred emailed submissions. They do accept postal submissions as long as these are only copies, and do not contain any original material.
It is important to browse their back catalog to get a good feel for what they publish, as they are clearly successful in their chosen niche. I would say most of what they publish is very much in tune with current trends and areas of interest.
Submission guidelines are detailed. They make it clear that they want both a title and a subtitle, as well as a one paragraph overview and a brief author biography, a thorough assessment of closely competing books, and an annotated table of contents. It is also important to include a sample chapter.
To learn more about their submission guidelines, go here.