A double-blind study means that neither the test subject (human) or the researcher administering the study knows whether the test subject is receiving the experimental treatment or the control treatment.
Often in human drug tests, the control treatment will be a placebo.
This ensures that neither party can make any expectations as to whether they should or shouldn't be seeing results. This is important because sometimes researchers will botch their results to coincide with their hypothesis. This also ensures that both control and experimental groups experience the "placebo effect" more or less equally
The best biometric design for a clinical trial is a double-blind trial comparing the drug against another drug, or placebo. This means that neither the doctor nor patient can tell which treatment the patient is on. To do this both treatments must look identical. Sometimes this is not possible, perhaps 1 drug is a pill, and one is a liquid. In this case biometrics dictates that a double blind double dummy design is used. A dummy liquid is made up to look like the active liquid, and a dummy pill is made up to look like the active pill. Patients then are given either the active pill and the dummy liquid, or the active liquid and the dummy pill.
By definition, the control group is what the experimental group is measured against. For example, if one is doing an experiment to measure the effect of a drug on blood pressure, the experimental group would receive the drug and the control group would receive the placebo, or blank. The blood pressure of both groups would be measured after ingestion of either the drug or placebo and any differences in blood pressure we would attribute to the effect of the drug. Care must be taken, however, that the two groups are as identical as possible and that all procedures are carried out identically. Furthermore, to eliminate even more bias, both the researchers and the experimental subjects would not know whether they were receiving drug or placebo (a double-blind study).
he was blind for about 4 years because of a experiment that went wrong
drug abuse could lead to drug addiction and dependence
Soap is not a drug.
drug therapies
Researchers use placebos to test the effectiveness of the drug on trial.
Blind and double blind testing is to ensure the results are not influenced by the people overseeing the test (or those undergoing the test where appropriate.)
Researchers use placebos to test the effectiveness of the drug on trial.
A placebo effect
Randomized controlled double blind trials is when the drug tester and the GP/Scientist both dont know what the drug is and the randomized and controlled bit means that they also don't know what they are testing the drug for e.g certain diseases but they are under observation and they are only being given tiny dosages incase of any after effects.
To prevent bias; neither the doctor or patient know who gets the drug so there is no way for subjective bias to be applied to either.
Double-blind studies control
Double Blind
The best biometric design for a clinical trial is a double-blind trial comparing the drug against another drug, or placebo. This means that neither the doctor nor patient can tell which treatment the patient is on. To do this both treatments must look identical. Sometimes this is not possible, perhaps 1 drug is a pill, and one is a liquid. In this case biometrics dictates that a double blind double dummy design is used. A dummy liquid is made up to look like the active liquid, and a dummy pill is made up to look like the active pill. Patients then are given either the active pill and the dummy liquid, or the active liquid and the dummy pill.
In a double-blind experiment, neither the researchers or the human test subjects know if they are receiving the tested medication or just a placebo (a harmless substance). This eliminates any bias by either the subject (who may psychologically influence his condition) or the experimenter (who may otherwise see effects that are not due to the treatment). While there are logistical and ethical questions that make double-blind experiments difficult, the ultimate aim is to definitively establish whether a drug or treatment actually works.
To avoid the placebo effect! If doctor knows that the substance he is giving is inert, his behavior will change. Patient is likely to note the same. If the doctor knows that he is giving the drug, his behavior will be confident. Patient will again note the same. So to avoid this placebo effect, the doctor has to be blind as well. Same is true for the patient also. So both the patient and the doctor need to be blind to have the proper study of the drug. Such study is called as double blind study and it is necessary for proper results.