ABSTRACT
Measurement is a procedure in which a researcher assigns numerals to empirical properties according to rules. There are four levels of measurement: nominal, ordinal, interval and ratio. This chapter focuses on these four levels of measurement. Nominal numbering implies belonging to a classification or having a particular property and a label. Ordinal scale is a ranking or a rating of data which normally uses integers in ascending or descending order. The numbering system in the ordinal and nominal measurement is purely an arbitrary label for identifying each type of person. If students have a set of observations or data where the distance between each observation is constant, then this type of measurement is called an interval level of measurement. Statistical probability will tell students whether any differences in scores are due to their manipulation of the variables, as predicted by their research hypothesis or, alternatively, only due to chance fluctuations as stated in the null hypothesis.
