In conventional PDD, NDI signifies that (1) the polygraph test recordings are stable and interpretable and (2) the evaluation criteria used by the examiner led him to conclude that the examinee was truthful to the relevant issue. The NDI and DI (Deception Indicated) decision options are used in specific- issue testing and correspond to NSR (No Significant Responses) and SR (Significant Physiological Responses) in multiple-issue, or screening, examinations.
