The nurse practitioner functions within an advanced practice framework that integrates autonomous clinical decision-making with collaborative interprofessional care. NP delegation requires sophisticated clinical reasoning that accounts for diagnostic uncertainty, disease complexity, and the need for timely intervention. Bayesian reasoning — updating the probability of a diagnosis based on new clinical evidence — guides the clinician in determining which diagnostic tests to order and in what sequence. Cognitive biases such as anchoring, availability heuristic, and premature closure represent significant threats to diagnostic accuracy and must be actively mitigated through systematic clinical reasoning frameworks.