In a double blind study
1. neither the persons collecting the data nor the subjects know all the details
of the study
2. the investigator is blind to the variables
3. the investigator can omit any data that fails to support the hypothesis
4. the investigators and subjects are not allowed to see each other
📠Explanation:
In a double-blind study, neither the participants nor the experimenters know who
is receiving the treatment or the placebo. This is to prevent any bias in the
study results due to the expectations of the participants or the researchers.
The statement that the investigator can omit data that fails to support the
hypothesis is not correct; data should be analyzed as is to maintain the
integrity of the study.