Quantitative Methods: Hypothesis testing

Question 1

What is the p-value?

Answer 1

Probability

Question 2

What is the threshold level (alpha value) usually for the p-value?

Answer 2

0.05

If p-value < 0.05 you reject your hypothesis

if p-value > 0.05 you accept your hypothesis

Question 3

What is the null hypothesis?

Answer 3

a hypothesis against the research
question, claiming that there is no difference in the result and the only
differences observed are just noise / error.

Question 4

In statistics, why do we test the probability that null hypothesis is true instead of the research hypothesis?

Answer 4

You can never prove something is true but can prove something is false

Ex) You found that students who brush their teeth every morning has a higher exam score.

What can be your precise research hypothesis? – toothbrushing improves your exam score? Could they just be more diligent than others?

Question 5

What is type-1 error?

Answer 5

False-positive

The vaccine is not effective but you conclude it is effective.

reject the null hypothesis when it is true

Question 6

What is type-2 error?

Answer 6

False-negative

The vaccine is effective but you conclude it is not effective

not to reject the null hypothesis when it is false