Reply by Les P. Beard to José Arce

Jose Arce is correct in his observation that the field results of Roy and Jain (1973) are in contradiction the synthetically derived results of Beard and Tripp. I agree that field observations must ultimately take precedence over synthetic results. If careful field measurements consistently contradict theoretical results, then the mathematical model must be regarded as inadequate. However, geological complexity makes a single case history no more convincing than a single theoretical study, and few in‐field IP array comparisons have been published.