Why are many schoolchildren still told to write up their science reports in the passive, as though experiments happened of their own accord? Many scientists abandoned this convention years ago. Watson and Crick's famous paper on the structure of DNA in Nature was in the active voice in 1953.

In scientific research, as in everyday life, our beliefs and biases often influence how we observe and interpret the world. In experimental psychology and clinical research, this problem is widely recognized, which is why experiments in these subjects are often carried out under blind or double-blind conditions. There is solid experimental evidence that experimenters' attitudes and expectations can influence the outcome of experiments.

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.

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.

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.

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.

Controversial biologist Rupert Sheldrake has recently published surveys suggesting that much of the current research in science may suffer from an important methodological problem that could seriously challenge the validity of many scientific findings. This article sets in motion a project designed to assess the impact of Sheldrake's provocative findings.