Nevertheless it succeeds in doing for potassium-argon dating what Willard Libby's book Radiocarbon Dating did for that radioactive clock; it provides a balanced and sufficiently comprehensive introduction to the subject for the nonspecialist user of the data." It appears that this book is a very introductory text and the quote you present from the creationist website could very likely be a part of an introductory explanation of how K-Ar dates are done. If you pull it out of context, it can look incriminating, especially to the lay person, but it seems like a pretty basic statement: "if the data you got from the lab agrees with the data you have, then the data from the lab is probably good".This book is written for someone who has collected samples, sent them to a lab, received a report with the lab's measurements, and wants to interpret what they're seeing. As for the claim that eight out of ten samples are discarded, I couldn't find a citation for that in your source.However, the general principles involved in radiometric dating apply across methods.
(Since it would be better science to blind the dating of the samples, by making sure that the source is unknown to the radiometric dating lab, why is this required?
) "The book grew out of a pamphlet written in response to requests from a number of US Geological Survey geologists who wanted a better understanding of potassium-argon dating.
The author attempted to preserve the simplicity of the original pamphlet while making the book more nearly complete and more useful.
As they point out in their preface, the book is not intended to be a scholarly or comprehensive review of potassium-argon dating, but rather an introduction to the principles, techniques, and applications of the method.
Approximately 8 out of 10 specimens ("dates") are discarded by radiometric dating labs because they are well out of range of age they "ought to be" given there source in the geological column.