Question

PLEASE HELP!!

Answer 1

Answer: d. Neither the researchers nor the experimental subjects know whether the latter have been assigned to an experimental group or a control  group.

Explanation:

A Double-blind design refers to a kind of experimental procedure aimed to reduce the possibility of any subjective biases on both the researchers and the participants. Mostly used in medical trials of drugs, double-blind experiments have participants randomly selected to be part of either the control or the experimental group. There´s a third party in charge of providing the random selection and encoding the information until the data collection is completed.