Surveys are consistently used to measure quality. Likert scales are a common ratings format for surveys. Statisticians have generally grouped data collected from these surveys into a hierarchy of four levels of measurement: 1. nominal data, 2. ordinal data, 3. interval data, and 4. ratio data. Likert scales were developed in 1932 as the familiar five-point bipolar response that most people are familiar with today. Your initial analysis of Likert scalar data should not involve parametric statistics but should rely on the ordinal nature of the data. While Likert scale variables usually represent an underlying continuous measure, analysis of individual items should use parametric procedures only as a pilot analysis. Combining Likert scales into indexes adds values and variability to the data. Finally, converting a five or seven category instrument to a continuous variable is possible with a calibrated line or track bar.