Illusionist Milbourne Christopher wrote years later that he felt "there are at least a dozen ways a subject who wished to cheat under the conditions Rhine described could deceive the investigator". When Rhine took precautions in response to criticisms of his methods, he was unable to find any high-scoring subjects. Another criticism, made by chemist Irving Langmuir, among others, was one of selective reporting. Langmuir stated that Rhine did not report scores of subjects that he suspected were intentionally guessing wrong, and that this, he felt, biased the statistical results higher than they should have been.