American Institute of Certified Planners (AICP) Practice Exam

Which type of data allows for some ranking but does not have fixed intervals between values?

1. Nominal data

2. Ordinal data

3. Interval data

4. Ratio data

The correct answer is: Ordinal data

The correct answer is ordinal data because it represents a type of qualitative data that allows for ordering or ranking of the values, indicating a relative position or preference. For instance, in a survey where respondents rate their satisfaction as "low," "medium," or "high," the categories can be ranked from least to most satisfied, but the exact difference in satisfaction between each level cannot be quantified as fixed intervals. In ordinal data, while one can determine which is greater or lesser, the lack of consistent intervals means that one cannot assume that the difference in rank corresponds to a specific measurement of value. For example, the difference in satisfaction between "low" and "medium" may not be the same as between "medium" and "high." The other types of data listed do not meet this definition. Nominal data is categorical and does not permit ranking at all, as it consists of distinct groups without any inherent order. Interval data, on the other hand, not only allows for ranking but also has fixed intervals between data points, making it possible to determine how much greater one value is compared to another. Ratio data contains all the properties of interval data plus an absolute zero, which allows for the comparison of absolute magnitudes.