As a rule, in the research context, variables can be represented on four levels. These are the nominal, ordinal, interval, and ratio-based ones (Maxfield, 2015). The specified approaches to measurement allow obtaining accurate data and assessing it accordingly. For example, the nominal-level variables may include data concerning the characteristics such as race and social background. For ordinal variables, details such as ethnicity may be presented, whereas the interval ones can be represented by IQ levels. Finally, ratio variables may provide information related to age and height.
The choice of the level on which a variable s captured largely depends on the goal with which the variable in question is intended to be used. While some variables are restricted to a specific level, thus, providing evidence that cannot be viewed from other perspectives, others offer a variety of interpretation opportunities, hence the necessity to introduce a specific angle from which they will be inspected (Maxfield, 2015). The specified opportunity to choose an analytical angle that will be applied for further analysis is instrumental in examining the possible correlations between the variables under analysis.
Furthermore, the choice of a specific level is predicated on the type of the analysis that must be conducted given the present objective. Specifically, the aims of the study determine the level on which a variable must be captured and studied accordingly. The specified approach to assessing variables allows examining the core information accurately and apply it to the case at hand accordingly. Finally, the selection of the level of analysis is largely determined by the limitations of a specific variable (Maxfield, 2015). Namely, the nature of variables typically reduces the range of available analysis levels. For instance, a variable such as ethnicity cannot be assessed as an ordinal or interval variable type. Thus, the level of analysis is linked closely to the nature of examined variables.
Reference
Maxfield, M. (2015). Basics of research methods for criminal justice and criminology (4th ed.). Cengage Learning.