ABSTRACT
Applying measurements appropriately in all sciences is a key skill. In the life sciences data comes in a range of forms that require different approaches to measurement. Some variables are continuous (or metric), which fall along an uninterrupted scale (e.g. length, mass, temperature) whilst count data can only be whole numbers and are categorical (also termed discrete, discontinuous or nonmetric). Four levels of measurement are recognized: the nominal, ordinal, interval and ratio scales.
