>>11757887in the context of making an experiment, blinding means withholding information which could influence the result of the experiment, for example
let's say that you want to test a new drug, you have to be sure that what you are seeing is the actual effect of the drug and not placebo/nocebo/effects, so you do this
you make 100 pills (random number) and 50 of them are the drug and 50 are sugar capsules, you make them totally identical so the people taking them cannot tell the difference
then you do not tell the researchers which kind of pill they are giving to the subjects (so they do not subtly influence the subject in an involuntary way).
then you can gather some experimental data, assuming you are able to filter out all of the other eventual data contaminations from the experiment itself.
this means that it becomes increasingly difficult to conduct proper experiments in a context where you cannot isolate a single element to test or where you do not know the interactions of that system (that happens with complex systems, like the brain).
this is also the issue with all of the fads in nutrition, food intolerances and diets because you cannot isolate a single component in a diet or be sure of the totality of the interactions of a certain molecule and the individual differences.
