effectively as possible to the stage at which he should be working. It should be pointed out, however, that for the most part it is only the advanced investigator himself who is likely to be especially concerned with verification at its most rigorous level. If our interpretation of the need for this volume is correct, it is probable that most of those concerned with actual methods, those who will undertake psi testing in one interest or another, will deal mainly with what in this chapter have been ranked as exploratory procedures. Let it be made clear, then, that there is no ranking of these methodological stages such that one can say the more rigorously controlled the test method the better. It may, in fact, be the worse if the situation calls for a free-moving, more exploratory approach. For example, in the wide range of what might be called clinical applications of psi tests, ready adaptability in method is so important that the more elaborate procedures and precautions of a crucial experiment should not even be considered.
Fortunately for parapsychology, however, some of those whose interest in psi begins as an incidental one may make first-rate discoveries that would call for further pursuit under the most advanced research design. Such an outcome is devoutly to be wished for and encouraged. If this general outline of the ways of investigating psi has been well enough presented to give an introductory picture, the inquirer, on whatever front, will be able to find or develop the plan of procedure best suited to his purpose.
The various adaptations of methods to particular uses such as clinical applications will doubtless develop many alterations; certainly as the interest in psi expands into adjacent fields, the methods will have to be adapted to fit the specialized needs. It will be advantageous, however, to maintain the same basic standards throughout and thus allow for easy comparison and interpretation of results across the boundary lines. The methods now in use will be found to adapt readily and widely without changing the basic structure.