# Relationship between nominal and ordinal data

### Correlation between a nominal and ordinal - Cross Validated

There are four measurement scales (or types of data): nominal, ordinal, interval For example, is the difference between “OK” and “Unhappy” the same as the. In general, the degree of association between a nominal variable and an ordinal variable can be assessed with Freeman's *theta *or a statistic. Nominal, Ordinal, Interval and Ratio are defined as the four fundamental levels of There are two primary ways in which nominal scale data can be collected: depict the order of variables and not the difference between each of the variables .

The difference between the two is that there is a clear ordering of the variables. For example, suppose you have a variable, economic status, with three categories low, medium and high. In addition to being able to classify people into these three categories, you can order the categories as low, medium and high. Now consider a variable like educational experience with values such as elementary school graduate, high school graduate, some college and college graduate.

These also can be ordered as elementary school, high school, some college, and college graduate. Even though we can order these from lowest to highest, the spacing between the values may not be the same across the levels of the variables. Say we assign scores 1, 2, 3 and 4 to these four levels of educational experience and we compare the difference in education between categories one and two with the difference in educational experience between categories two and three, or the difference between categories three and four.

The difference between categories one and two elementary and high school is probably much bigger than the difference between categories two and three high school and some college. In this example, we can order the people in level of educational experience but the size of the difference between categories is inconsistent because the spacing between categories one and two is bigger than categories two and three.

If these categories were equally spaced, then the variable would be an interval variable.

## What is the difference between categorical, ordinal and interval variables?

Interval An interval variable is similar to an ordinal variable, except that the intervals between the values of the interval variable are equally spaced. Why does it matter whether a variable is categorical, ordinal or interval?

Statistical computations and analyses assume that the variables have a specific levels of measurement. For example, it would not make sense to compute an average hair color.

An average of a categorical variable does not make much sense because there is no intrinsic ordering of the levels of the categories.

- Types of Data & Measurement Scales: Nominal, Ordinal, Interval and Ratio
- What is the difference between ordinal, interval and ratio variables? Why should I care?

Moreover, if you tried to compute the average of educational experience as defined in the ordinal section above, you would also obtain a nonsensical result.

Because the spacing between the four levels of educational experience is very uneven, the meaning of this average would be very questionable. In understanding what each of these terms mean and what kind of data each refers to, think about the root of each word and let that be a clue as to the kind of data it describes.

Nominal data involves naming or identifying data; because the word "nominal" shares a Latin root with the word "name" and has a similar sound, nominal data's function is easy to remember. Ordinal data involves placing information into an order, and "ordinal" and "order" sound alike, making the function of ordinal data also easy to remember. For example, the results of a test could be each classified nominally as a "pass" or "fail.

For example, test results could be grouped in descending order by grade: Nominal Data Nominal data simply names something without assigning it to an order in relation to other numbered objects or pieces of data. An example of nominal data might be a "pass" or "fail" classification for each student's test result.

Nominal data provides some information about a group or set of events, even if that information is limited to mere counts.

### What Is the Difference Between Nominal & Ordinal Data? | Sciencing

For example, if you want to know how many people were born in Florida each year for the past five years, find those figures and plot your results on a bar graph. The data represented on the graph have no natural ranking or ordering; the numbers simply illustrate a fact, not necessarily a preference, and are just labels that answer the question "how many? Sciencing Video Vault Ordinal Data Ordinal data, unlike nominal data, involves some order; ordinal numbers stand in relation to each other in a ranked fashion.