Physical Sciences
If the signal being measured is actually smaller than the rounding error and the data are over-averaged, a positive result for the measurement can be found in the data where none exists (i.e. a more precise experimental apparatus would conclusively show no such signal). If an experiment is searching for a sidereal variation of some measurement, and if the measurement is rounded-off by a human who knows the sidereal time of the measurement, and if hundreds of measurements are averaged to extract a "signal" which is smaller than the apparatus' actual resolution, then it should be clear that this "signal" can come from the non-random round-off, and not from the apparatus itself. In such cases a single-blind experimental protocol is required; if the human observer does not know the sidereal time of the measurements, then even though the round-off is non-random it cannot introduce a spurious sidereal variation.
Read more about this topic: Experimenter's Bias
Famous quotes containing the words physical and/or sciences:
“For pain is perhaps but a violent pleasure? Who could determine the point where pleasure becomes pain, where pain is still a pleasure? Is not the utmost brightness of the ideal world soothing to us, while the lightest shadows of the physical world annoy?”
—Honoré De Balzac (1799–1850)
“The well-educated young woman of 1950 will blend art and sciences in a way we do not dream of; the science will steady the art and the art will give charm to the science. This young woman will marry—yes, indeed, but she will take her pick of men, who will by that time have begun to realize what sort of men it behooves them to be.”
—Ellen Henrietta Swallow Richards (1842–1911)