What can be observed either directly or indirectly is a set of traits of some concrete system. If observation is to be precise it must be quantitative because concrete systems have quantitative properties, if only because they exist in determinate amounts and in spacetime. Quantitative observation is measurement. Whenever numbers are assigned to certain traits on the basis of observation, measurements are being taken. There are as many kinds of measurement as kinds of properties and measurement techniques. Essentially we can count, compare, or measure in a strict sense. In order to decide what kind of measurement is to be done, an analysis of the concept denoting the corresponding property must be performed. Accordingly the nature of quantification must be analyzed before the features of measurement can be understood.