In Section 1.3 it was pointed out that the subject matter of “statistics” is very broad and has been subdivided into the more or less distinct subdisciplines of “parameter estimation,” “hypothesis testing,” “regression analysis,” and “quality control.” The subject matter of this book is oriented primarily toward parameter estimation or “sampling.” However, persons engaged in parameter estimation must have some background in the concepts underlying the procedures used in the testing of hypotheses, which forms the framework within which much research and development are done. This chapter is designed to provide this fundamental background. It certainly will not be complete. For more complete coverage, the student is referred to standard statistical texts such as those by Snedecor and Cochran (1967), Steel and Torrie (1960), Sokel and Rohlf (1969), Miller and Freund (1977), or Mendenhall and Shaeffer (1973).