Analysis of Continuous outcomes

Question 1

What is a type I error?

Answer 1

A type I error occurs when we reject the null hypothesis when it is in fact true

Question 2

What is a type II error?

Answer 2

A type II error occurs when we accept the null hypothesis when it is not true

Question 3

What is the probability of a type I error?

Answer 3

P(Type I error)= Level of significance (alpha)

Question 4

What is the probability of a type II error?

Answer 4

P(Type II error)=1-Power (beta)

Question 5

What is the significance of using type II error before the trial?

Answer 5

The type II error should be explicitly defined when the study is designed in order to calculate the sample size needed to ensure the study has sufficient power to detect the given effect

Question 6

What assumptions are made for two sample t-tests and confidence intervals?

Answer 6

(I) subjects are independent
(II) the variances of the two populations being compared are equal
(III) Data in each population are normally distributed