How things are measured is of great importance, because the method used for measuring the qualities of a variable gives researchers information about how one should be interpreting those measurements. Similarly, the precision or accuracy of the measurement used can lead to differing outcomes of research findings, and it could potentially limit the statistical analyses that could be performed on the data collected.

Measurement is generally described as the assignment of numbers or labels to qualities of a variable or outcome by following a set of rules. There are a few important items to note in this definition. First, measurement is described as an assignment because the researcher decides what values to assign to each quality. For instance, on a football team, the coach might assign ...