Insight #5: The commentator must not assume that his audience consists of 'ideal readers.'
While real authors, however, hope for ideal readers, they are unlikely, if they have reflected on the matter (or even if not), to assume ideal readers. Real authors are content with something less than an ideal reception of the text. They will be looking for successful and effective communication, not ideal communication; and they will expect to communicate to different degrees and at different levels. ...Despite all appropriate qualifications and limitations, I want a commentator to write with a confidence that a real writer has successfully communicated with real readers in a transaction that can be ultimately satisfying for both parties. (308-309, italics original)