In case you are unfamiliar with the term, or need some memory jogging, the experimenter effect is a phenomenon where the outcome of an experiment relies on the beliefs of the person running it.
Now I am referring to an article, the details:
New Scientist, 13 March 2004. Special Report: The Power of The Paranormal. The power of belief; John McCrone.
Now to cut a long story short on his article, it discusses the re-emergence of the “experimenter effect” into the psychic “powers” debate.
Basically, a pair of scientists (Richard Wiseman - psychologist at University of Hertfordshire, UK; Marilyn Schlitz - parapsychologist at Institute of Noetic Sciences, Petaluma, California) are testing this “experimenter effect”. It is thought that by running two seperate experiments (one done by the skeptic - Wiseman; the other carried out by the believer - Schlitz) that some sort of statistical analysis will reveal whether or not there really is an experimenter effect.
The idea is that when the believer runs the experiment, she will obtain data that is statistically in favour of psychic phenomena. Whereas when the skeptic tries the experiment, he will obtain data that statistically does NOT support psychic phenomena.
It goes without saying that both of the scientists will conduct FAIR experiments, so we should assume that they have maintained thier integrity (and objectiveness).
So my question(s) is(are):
How well documented is this “experimenter effect”?
What could possibly (in the known laws of science) be causing an experimenters belief alone to change the RESULT(s) of the experiment?
In any experiments, assuming that perfect physical conditions exist (which I know is a practical impossibility) so that outside interference is minimal or zero, can an experimenters belief alone change the nature of the experiment (and thus the data we obtain from it)?
If we assume that the answer to number 3) is YES, then is BELIEF alone a sufficient tool/mechanism that will change an experiment? Could it not be something even deeper, like our own perceptions of the experiment itself (i.e. the observer causing a direct change upon the experiment though no DIRECT PHYSICAL CONTACT is made)?
And if so, then what implications does this have as a whole for scientific experiments?