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Can you use paired t-test on ordinal data?
T-tests are not appropriate to use with ordinal data. Because ordinal data has no central tendency, it also has no normal distribution. Because of this, a t-test of ordinal data would have no statistical meaning.
Is t-test ordinal or nominal?
t–test: independent variable is nominal, but dependent variable is ratio/interval. 4.
What are the three assumptions for the paired samples t-test?
Assumptions
- The dependent variable must be continuous (interval/ratio).
- The observations are independent of one another.
- The dependent variable should be approximately normally distributed.
- The dependent variable should not contain any outliers.
Is categorical data ordinal?
Ordinal data is a categorical, statistical data type where the variables have natural, ordered categories and the distances between the categories are not known. The ordinal scale is distinguished from the nominal scale by having a ranking.
What are the assumptions for a paired sample t-test?
Assumptions mean that your data must satisfy certain properties in order for statistical method results to be accurate. The assumptions for the Paired Samples T-Test include: Let’s dive in to each one of these separately. The variable that you care about (and want to see if it is different between the two groups) must be continuous.
Why does paired t test not work with ordinal data?
Because this is ordinal data, the assumptions that the data follow a normal distribution will be violated. Given that the assumption of normality is violated, a typical paired t-test in this situation would at best lack sensitivity, and at worst provide spurious estimates.
Can a paired t-test be run on continuous data?
These are the reading levels from k – 8th grade. I was able to run a paired t-test on the continuous data, which was a standardized test with grade level equivalency, but I am not sure if I can also do it for the reading level data. Because this is ordinal data, the assumptions that the data follow a normal distribution will be violated.
When to assume normality in paired t test?
All the points fall approximately along the (45-degree) reference line, for each group. So we can assume normality of the data. Note that, if your sample size is greater than 50, the normal QQ plot is preferred because at larger sample sizes the Shapiro-Wilk test becomes very sensitive even to a minor deviation from normality.