In a single blind study, only the investigator knows what is to be used on the subject, this has its advantages since the investigator in this case has complete control over what is given; however, this can also induce some bias from either the investigator him/herself or the subject should the investigator do a poor job in hiding the contents of the test. A double blind study is meant to remove this bias since neither investigator nor subject knows what is being administered. Since neither party knows of the contents of say, a new drug, the study can progress without the fear of skewed results. Furthermore, although the subject will have to sign a consent form, they will not know whether or not they are receiving a placebo (if there is one). That way, the subject’s own beliefs will not hinder the results and “truer” data can be extracted in this manner. The only downside may be that the investigator will may not know what to do in the case of certain mishaps or effects; however, it is implied, given that there is a human subject involved, that someone in the vicinity such as a head researcher is nearby in order to oversee the double blind study. For a intents an purposes, a double blind study appears to be the optimal way to achieve unbiased results in a clinical trial.