Direct scaling procedures, such as magnitude estimation, provide an efficient way to answer one of the fundamental questions traditionally studied in psychophysics; that is, they provide a method to quantitatively define how much sensation is present. But why is this useful? When and why do we care how much sensation is there? As it turns out, sensation often needs to be quantitatively defined for many different purposes. Applications of scaling can be found in a broad range of research areas. Read on to take a quick look at how scaling has been used in the worlds of ergonomics and medicine.