Control of extraneous variables, minimizing the potential for experimenter bias, counterbalancing the order of experimental tasks, adequate sample size, the use of operational definitions, emphasis on both the validity of results, and proper statistical analysis are central to experimental methods in psychology.
12.
Several independent experimenters were unable to find evidence beyond statistical randomness that people could tell they were being stared at, with some saying that there were design flaws in Sheldrake's experiments, In 2005, Michael Shermer expressed concern over confirmation bias and experimenter bias in the tests, and concluded that Sheldrake's claim was unfalsifiable.
13.
Having donned the trappings of expertise and put themselves out as authorities, they incurred what John Erskine called'the moral obligation to be intelligent .'Long before they even thought to put pen to paper and write their extravagant tales of extra-ordinary awakenings, they should have heeded not just the technical lessons of Clever Hans, but the findings of more than a century of scientific and practical investigations of automatic writing, experimenter bias, mental telepathy, unconscious influence, subjective validation, stimulus leakage, expectancy effects, deception and self-delusion.
