ADJ (试验或研究)双盲的（指研究人员和被试验者均不知哪一组试验者正接受测试） A double-blind study or experiment compares two groups of people, one of which is being tested while the other is not. Neither the people doing the testing nor the members of the two groups know which group is being tested. (试验或研究)双盲的（指研究人员和被试验者均不知哪一组试验者正接受测试）
In a double-blind trial, there were definite improvements.