Question

How does a reader determine the credibility of a narrator?

1)by evaluating whether or not the narrator is actually the speaker
2)by determining whether or not the narrator is the same as the author
3)by examining the balance and consistency of information provided by the narrator
4)by judging if the narrator is realistic enough to trust

Answer 1

I would say that the best answer is this one:

3)by examining the balance and consistency of information provided by the narrator

I understand a credible narrator to be consistent: this means that a picture they provide is not dependent on a moment's whim, but even if it's biased; it's biased in a predictable way.

Answer 2

A reader determines the credibility of a narrator by examining the balance and consistency of information provided by the narrator.

A reliable narrator should be in the vicinity of the values to the implied author. The narrator should be able to illustrate the knowledge of the character and the situation deeply. The narrator should be able to distance himself or herself from personal relations with the characters so that it displays an unprejudiced account.