The First Edition of this book was published in 1937 with George W. Snedecor as the sole author. Snedecor asked William G. Cochran to do the revisions for the sixth edition, and Cochran was listed as the second author of the sixth and seventh editions. The present edition was prepared by several members of the Department of Statistics at Iowa State University. The revisions were guided by the principle that the work should remain the work of its original authors; thus, much of the material remains as previously published. A significant change in this edition occurs in the notation used to describe the operations of multiple regression. Matrix algebra replaces the original summation operators, and a short appendix on matrix algebra is included.
I used this book in a summer school university course "Statistical methods for Natural Scientists". Many tables, many methods presented for analyzing data such as determining which data points are true outliers or should be kept, confidence intervals, just to name a minute portion of the realm of this book.
I may not be remembering correctly, it was 45 years ago, but I think this book was a landmark for statistics and introduced new methods and compiled existing methods into one reference book that made the field of statistics more complete and accesible.