Statistical Tests Flashcards
What is the purpose of statistical tests?
To determine whether difference or correlation in data is significant or due to chance
Types of statistical tests
Chi squared
Student’s t-test
Spearman’s rank
When is chi squared used?
To compare observed and expected data
When is student’s t-test used?
To compare means
When is spearman’s rank usedV
Correlation coefficient
- to identify and test the strength of a relationship between to sets of data
What do the statistical tests produce?
Each test produces a number (calculated value)
How do you use the number produced by statistical tests?
Use a probability table
Critical table: 0.05
- 5% likely to chance
- 95% likely to chance
What if p ≤ 0.05 in a statistical test?
Difference is significant
0.05 or less probability that the data is due to chance
Reject null hypothesis
What if p ≥ 0.05 in a statistical test?
Difference isn’t significant
Probs of it being due to chance is > 0.05
Accept null hypothesis
What is a null hypothesis?
A hypothesis in which there is no statistical relationship between a set of observations (observed variables)
