There are many tools available for exploring and describing single variables in data sets, including descriptive statistics, frequency tables and various descriptive graphs. We will explore some of these tools here. Measurement, or scale data, is data that can be measured in precise units. Each value represents a single measurement for that data case.
Categorical data contains values that represent a level of a certain category.
With Ordinal data, there is some significance to the ordering of the data values. With nominal data, there is no significance to the ordering of the values. For instance, Education Level may be an ordinal variable but School Region would be a nominal variable. Different types of analysis tools are available for analyzing categorical and measurement data. Basic descriptive statistics give information about the distribution of a scale or measurement variable.