Ordinal scale has natural or intrinsic order in its different items or values. For example when dealing with various education levels we say primary, middle, secondary, under graduate and post graduate education. Here order exists among various levels of education. And we know that a person with primary level of education is less educated than a person with middle level of education and so on. Similarly when dealing with teaching profession we say elementary school teacher, secondary school teacher, higher secondary school teacher, lecturer, assistant professor, associate professor and professor etc. Here we know that elementary school teacher is lower in rank than secondary school teacher and secondary school teacher is lower in rank than lecture or professor. Similarly you can think of various ranks of military personnel like lieutenant, captain, major and lieutenant colonel etc. Various stages of human life like infancy, childhood, adolescence, adulthood, and old age is another example of ordinal scale. Likert scale, Bogardus Social Distance Scale, Tharstone Scale and Semantic Differential Scale are some additional examples of nominal scale. In ordinal scale, though we know that there is a difference among its various items or values but we can't say how much is it. Nominal and Ordinal scales are sometimes called nonparametric scales which means that parametric statistics can’t be used with them. The other three types of scales are: nominal, interval and ratio.
