Katie, Alex, and a Mr. Williams

The game Williams is talking about was the act of him inserting errors into the paper purposely for the reader to find.

He is saying errors are less objective and more subjective. They depend on the person editing them. What looks like an error to one person might not be an error to somebody else.

He locates errors in both the writer and the reader because the error had to be in the mind of the writer and the error also had to be in the mind of the reader that caught it.

He is reiterating his point that the error is subjective.