The reason for double-blind tests is that people who know they're receiving the experimental intervention expect a certain result from it, and report that result. It is almost impossible to determine how much of the effect they report is due to the experimental intervention, and how much is due to their expectations. A double-blind test helps to control for that complication.
The test is double-blinded because if it were only single-blinded, the person giving the pills could unconciously communicate whether they are giving drug or placebo and skew the result. Only when neither the researcher nor the subject knows which is which does it become truly possible to determine the effects of the drug. Even then, it's not straightforward; it can still take some heavy-duty statistical analysis to figure out if an effect is real.
Edm,
Yes, I know what a double blind test is and the reasons for having them very well. I commented that it really isn’t necessary for a double blind test to be done for aspartamine in your comment to null and void. A single blind would suffice if it is set up correctly. The adminstrator of the test does not necessarily unconciously communicate what they are giving.
Edm,
Yes, I know what a double blind test is and the reasons for having them very well. I commented that it really isn’t necessary for a double blind test to be done for aspartamine in your comment to null and void. A single blind would suffice if it is set up correctly. The adminstrator of the test does not necessarily unconciously communicate what they are giving.