Precision, Validity, and Repeatability of Measurements and Diagnostic Tests

Measuring is one of the most common things that we do every day in our lives and careers. A lot of our decisions depend on the size we get. For example, to prescribe the right amount of insulin to a diabetic patient or the amount of blood for a patient with severe bleeding, we need the patient’s blood sugar and hemoglobin levels. If these measurements are not correct, we will make an error in our decision. In determining cause-and-effect relationships or diagnostic tests, it is also necessary to pay attention to concepts such as accuracy, validity, and reliability. In this chapter, these indicators are discussed.