Choosing a statistical test Flashcards
spearman’s rho
a test for correlation when data is at least ordinal level
pearson’s r
a parametric test for a correlation when data is at interval data
wilcoxon
a test for a difference between two sets of scores data should be at least ordinal level using a related design
mann - whitney
a test for difference between two of scores which data must be interval level with an unrelated design
related t - test
a parametric test for a difference between two sets of scores that data must be interval level with a related design
unrelated t - test
a parametric test for a difference between two sets of scores that data must be interval level with an unrelated design
chi - squared
a test for an association between two variables or conditions which data should be nominal level using an unrelated design
what are the three steps to choose a statistical test ?
- whether a researcher is looking for a difference or correlation
- in case of a difference, what experimental design is used
- the level of measurement
what are the different levels of measurement quantitive data can be classified into ?
-Nominal
-Ordinal
-Interval
what is Nominal data ?
- Nominal data is data that can be categorised.
-Data could only be in 1 group or another.
-Discrete data
what is ordinal data ?
-Data that can be ordered in some way.
-Is subjective (down to individual/ personal to individual)
- No equal intervals between values.
-Subjective
what is interval data ?
-Data based on numerical scales.
- Objective
-Equal intervals between values
-Most sophisticated
-Well established scale
what is the measure of central tendency for each of the level of measurements ?
nominal - mode
ordinal - median
interval - mean
what is the measure of dispersion for each of the level of measurements ?
nominal - none
ordinal - range
interval - standard deviation
give an example of the level of measurement of statistical testing
nominal - girls or boys
ordinal - scores on a IQ test
interval - height and weight
