ABSTRACT
According to S.S.Stevens (1951), “In its broadest sense measurement is the assignment of numerals to objects or events according to rules” (p. 1). As we have seen in chapter 4, the process of research begins with a problem that is made up of a question about the relationship between two or more variables. Measurement is introduced when these variables are operationally defined by certain rules that determine how the participants’ responses are translated into numerals. These definitions can include unordered categories in which the numerals do not indicate a greater or lesser degree of the characteristic or the variable. Stevens went on to describe four scales of measurement that he labeled: nominal, ordinal, interval, and ratio. These types of measurements vary from the unordered (nominal) to the highest level (ratio). However, because none of the statistics that are commonly used in social sciences or education require the use of ratio scales, we will not discuss them extensively. Furthermore, this categorization is not the most useful one for determining which statistics are appropriate, so we present an alternative categorization proposed by Helena Chumura Kraemer (personal communication, March 16, 1999).
