Clear and accurate--but this lengthy guide to one simple method of barrier birth control is overdoing it. The cervical cap--basically, a smaller, more compact diaphragm that can be left in place for several days--has been in use in Europe for decades. It is currently being tested in this country and expected to be FDA-approved sometime in 1988. Fine, but Chalker just goes overboard in her advocacy: here we start with ""Myths and Realities of the Cervical Cap""; ""The 150-Year History of the Cervical Cap""; ""The Cervical Cap Renaissance""; how to fit it; how to find a practitioner to fit it; use and care of the cap; possible problems to consider, and so on, and on. That the cap is a convenient and reliable method of birth control is beyond dispute, and Chalker is well-organized and readable. But would-be cap-users would do just as well with a descriptive pamphlet on the device.