"This manual is intended primarily for field operators, not theorists. While we believe the principles underlying each technique are correctly presented, a rigorous analysis is absent. Such an approach would have done little to increase the usefulness of the study and, in general, the wrong persons would have written them. Gulf's Rawlins Field Test No. 2 is used as an example of how to employ the matrix in selecting the instrumentation and techniques within the constraints of actual practice."