What do binomial tests find out?
If the proportion in your data is what would be expected by chance
It compares an observer proportion with an expected frequency
What are the assumptions of binomial tests?
Data are nominal
Single dichotomy (one variable with 2 mutually exclusive outcomes)
Scores are from a random sample of population
Data are independent
You know expected distribution of scores (chance level)
What is the difference between binomial and chi-square tests?
Binomial tests one sample vs expected frequency
Chi-square tests one sample vs another sample
What are the assumptions of chi-square test of independence?
Data are nominal
There are 2 dichotomies
Scores are from random sample
Data are independent
Sample size at least 40
Each category must have expected N of 5 or above
What is the calculation of chi-square?
Sum ((observed-expected)^2)/expected for each cell
What is the non-parametric alternative to chi-square?
Fisher’s exact test
What is a one-tailed hypothesis?
A directional hypothesis
What is a two-tailed hypothesis?
A non directional hypothesis
