The times in which written evidence is best are two-fold. First written evidence is best when those that need the information are numerous in number and wide in physical location. For example, if class were to be cancelled by a professor, the professor would not go up to each individual and tell him or her personally that class is cancelled, as this would be a very tiresome task. Rather, the professor would send the information in a written form to all students at one, such as through email. Finally, written evidence is best when the information that is shared can no longer be shared through any other means. For example, if one wanted evidence that Aristotle was a short man, one today cannot simply walk up to Aristotle and measure him as he has been dead for many a century. To find out this information, it would be best to consult a written form such as a book about Aristotle.
In conclusion, information or evidence can be shared and gathered in numerous ways. Information that needs to be given to a wide and numerous audience and information that can be gathered in no other way are examples of when the written form is best suited.