eM1 – Principles of hypothesis testing Flashcards
What is a research question?
Provides the frame for which every component of a research project refers back to - everything read experimented and discussed must link back to it
What is a hypothesis?
A prediction of what the answer to a research question may be
How do we test the validity of a hypothesis
Carefully chosen statistical tests
What is a null hypothesis?
A prediction that there is no dependant relationship between two variables
What is an alternative hypothesis?
A prediction that there is a specific and reproducible (dependant) relationship between variables
Why in clinical practice would you prefer a non directional hypothesis?
In case you miss an effect from what you’re testing
What is important to remember about testing the validity of null hypotheses?
Can only reject or fail to reject chosen null hypothesis- answer is most likely correct but isn’t 100% conclusive
What is a p-value?
The likelihood that the observed difference was observed by chance
What is the significance of a p-value?
Calculates the probability that the observed results are real - the probability of the results of the study reflecting what would be observed in the population.
What is the alpha (a)-value?
The probability of rejecting the null hypothesis when it’s true.
At what a-value do most consider the p-value to show a significant difference?
p ≤ a = 0.05
When do we reject the null hypothesis?
p ≤ 0.05
Draw the statistical dicision tree
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What tests are used to test differences
Chi squared test
ANOVA
T-tests
Kruskal-Wallis
Wilcoxon
Mann-Whitney U-test
What test are used to test for simmilarities or correlations
Chi squared test
Pearson
Spearman Rank
