Is GPA (1.0-4.0) nominal, ordinal, or scale variable? Is level of anxiety (low to high) nominal, ordinal, or scale variable?
The Correct Answer and Explanation is:
Correct Answers:
- GPA (1.0–4.0) is a scale variable (specifically, it is a ratio or interval scale depending on context).
- Level of anxiety (low to high) is an ordinal variable.
Explanation:
1. GPA (Grade Point Average)
GPA is considered a scale variable because it has numeric values that are ordered, measurable, and meaningful. It typically ranges from 1.0 to 4.0 in many education systems. It falls under the interval scale because the difference between values (e.g., the difference between 3.0 and 2.0) is consistent and meaningful. However, GPA does not have a true zero point. A GPA of 0.0 does not mean the total absence of learning or intelligence—it simply reflects academic performance. Because there is no absolute zero, GPA is most often classified as interval scale rather than ratio.
Scale variables support a wide range of statistical analyses. You can calculate mean, median, standard deviation, and perform parametric tests with GPA data. This level of measurement is useful for comparing students and evaluating performance in a standardized and quantitative way.
2. Level of Anxiety (Low to High)
The level of anxiety described with labels like low, moderate, and high is an ordinal variable. This is because it reflects a meaningful order or ranking, but the intervals between the levels are not equal or measurable. For example, the difference in anxiety between “low” and “moderate” might not be the same as between “moderate” and “high.”
Ordinal data cannot be used to calculate precise means or standard deviations. Instead, you can analyze it using medians, modes, and non-parametric tests. Though useful for ranking, ordinal data lacks the precision and mathematical properties of scale variables.
In conclusion, GPA is a scale (interval) variable, while levels of anxiety are best treated as ordinal.
