ABSTRACT
The development of modern science rested on careful measurement. Boyle's law resulted from the ability to measure both pressure and temperature of a gas. Sir Isaac Newton's laws of motion assumed that speed could be measured and presented as specific numbers. Consider Chronic Obstructive Pulmonary Disease (COPD), where the lungs have lost some of their resiliency, and the patient finds it difficult to breathe in and out. COPD is usually a disease of smokers and involves permanent damage to the lungs that continues long after the patient has stopped smoking. One way developed for measuring COPD is to have the patient blow as hard as he or she can into a tube, where the air is evacuated as it flows in, so there is no air pressure pushing back. One final warning about the use of statistical models: The estimated model describes the structure of the data that have been observed.
