Scientific Papers on Experimenter Effects

Personally speaking

New Scientist, July 19, 2001
by Rupert Sheldrake
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Abstract
Most scientific journals accept papers in the active voice and some, including Nature, positively encourage it. When I surveyed the current issues of 55 journals in the physical and biological sciences I found only two that still required contributors to use the passive.

How Widely is Blind Assessment Used in Scientific Research? Alternative Therapies

5(3), 88-91, May 1999
by Rupert Sheldrake
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Abstract
In everyday life, as in scientific research, "our beliefs, desires and expectations can influence, often subconsciously, how we observe and interpret things", as a recent article in the Skeptical Inquirer expressed it.(note 1) In experimental psychology and clinical research, these principles are widely recognized, which is why experiments in these subjects are often carried out under blind or double-blind conditions. There is overwhelming experimental evidence that experimenters' attitudes and expectations can indeed influence the outcome of experiments.

Experimenter Effects in Scientific Research: How Widely are they Neglected?

Journal of Scientific Exploration 12, 73-78, 1998
by Rupert Sheldrake
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Abstract
A survey of recent papers published in a range of scientific journals showed that the used of blind methodologies is very rare in the so-called hard sciences. In the physical sciences, no blind experiments were found among the 237 papers reviewed. In the biological sciences, there were 7 blind experiments out of 914 (0.8%). There was a higher proportion in the medical sciences, 6 out of 102 (5.9%), and in psychology and animal behaviour, 7 out of 143 (4.9%). By far the highest proportion (85.2%) was in parapsychology. A survey of science departments in 11 British Universities showed that blind methodologies are neither used nor taught in 22 out of 23 physics and chemistry departments, or in 14 out of 16 biochemistry and molecular biology departments. By contrast, blind methodologies are sometimes practised and taught in 4 out of 8 genetics departments, and in 6 out of 8 physiology departments. I propose a simple procedure that could be used to detect possible experimenter effects in any branch of science, by comparing the results of a given experiment conducted both under open and blind conditions.

Could Experimenter Effects Occur in the Physical and Biological Sciences?

Skeptical Inquirer 22(3), 57-58 May / June 1998
by Rupert Sheldrake
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Abstract
Probably most skeptics would agree with Michael Mussachia (SI Nov/Dec 1995) that "our beliefs, desires and expectations can influence, often subconsciously, how we observe and interpret things". In psychology and clinical medicine these principles are widely recognized, which is why experiments in these subjects are often carried out under blind or double-blind conditions.