In order to write a perfect and accurate biography, the writer needs to do in-depth research to dig into all information, from the largest bit to the smallest detail of the person. This means that the writer would need access to personal interviews, existing written documents, photographs, and any relevant documents or artifacts that can be of significant importance to the events in the person's life. The writers would also require interviews with relatives and friends of the person, and if the person is alive, then their interview as well. Detailed information is really important about that person so that the biography is as accurate as possible.