Significance Tests and P-Values

Question 1

Why do you need significance tests?

Answer 1

To be sure if a new treatment or drug is actually effective

Question 2

What is a null hypothesis?

Answer 2

It’s the assumption about the population of interest

Usually in the form of there is no real difference or there is no real association

Question 3

What is a P-value?

Answer 3

It’s a probability between 0 and 1

It weighs the evidence against the null hypothesis

Question 4

How to interpret p<0.05?

Answer 4

This is good evidence to reject the null hypothesis and that a real association does exist

Question 5

How to interpret p>0.05?

Answer 5

There is insufficient evidence to reject the null hypothesis and the result is then not statistically significant

Question 6

When is a P-value significant?

Answer 6

A p-value less than 0.05 is not statistically significant and it indicates strong evidence for the null hypothesis

Question 7

What does it mean if something is clinically significant?

Answer 7

Means the difference observed is large enough to be clinically meaningful

Question 8

What is a 2 sided significance test?

Answer 8

Where you have a null hypothesis and an alternative hypothesis

Question 9

What is a 1-sided significance test?

Answer 9

Used when the null hypothesis and alternative hypothesis oppose each other directly

Question 10

2 sided or 1 sided tests?

Answer 10

Always use 2 sided as it can distinguish harmful effects