How reliable the domains and authors you've analyzed look, based on your own documents.
Each document gets a quality score from its analysis: how well reasoned it is (35%), how much important information it carries (15%), low propaganda (20%), low sales/marketing/advertising content (10%), and the strength of its premises (20%), minus a penalty for fallacies. A source's reputation is the average of its documents' scores, pulled toward a neutral 50 when there are few of them, so a single article never decides a verdict. Confidence grows with the number of documents.