blind experiment // canavarlar

Double-blind describes an especially stringent way of conducting an
experiment, usually on human subjects, in an attempt to eliminate
subjective bias on the part of both experimental subjects and the
experimenters. In most cases, double-blind experiments are held to
achieve a higher standard of scientific rigour.

In a double-blind experiment, neither the individuals nor the researchers
know who belongs to the control group and the experimental group. Only
after all the data has been recorded (and in some cases, analyzed) do the
researchers learn which individuals are which. Performing an experiment in
double-blind fashion is a way to lessen the influence of the prejudices and
unintentional physical cues on the results (the placebo effect, observer
bias, and experimenter's bias). Random assignment of the subject to the
experimental or control group is a critical part of double-blind research
design. The key that identifies the subjects and which group they
belonged to is kept by a third party and not given to the researchers until
the study is over.

Double-blind methods can be applied to any experimental situation where
there is the possibility that the results will be affected by conscious or
unconscious bias on the part of the experimenter.

Computer-controlled experiments are sometimes also referred to as
double-blind experiments, since software should not cause any bias. In
analogy to the above, the part of the software that provides interaction
with the human is the blinded researcher, while the part of the software
that defines the key is the third party. An example is the ABX test, where
the human subject has to identify an unknown stimulus X as being either A
or B.

Triple-blind trials

Triple-blind trials are double-blind trials in which the statistician
interpreting the results also does not know which intervention has been
given. Sometimes triple-blind is used to mean that multiple investigators
are all blinded to the protocol (such as the clinician giving the treatment
and a radiologist or pathologist who interprets the results.) The use of the
term triple-blind experiments is disputed.

http://en.wikipedia.org/wiki/Double-blind