First of all, the disability must be established by credible medical evidence, and that comes from physicians, whether it's independent physicians, whether it's.... It would be in the file. The representative of the applicant would present that evidence.
As far as the members are concerned, we receive our directions from the Federal Court on how to assess a credible medical opinion. We have cases that have given the tribunal directions on how to determine a credible medical opinion, and that would be that's it from a qualified medical physician; that it's based on as full and complete a medical history of the individual as possible; and that there is a conclusion based on that medical information where the physician provides an opinion.
Perhaps there are multiple medical opinions in the file. It is the obligation of the tribunal to review all that material. With this evidence, together with any witnesses and the applicant's own testimony, we make a finding of whether to vary the decision that was previously made by the department.