EIP - χ2 and t-test - Week 9

Question 1

What is a t-test used to assess?

Answer 1

To know if the apparent difference between sample distributions is real (they are from different populations) or if it is due to random variation (they come from the same population)

Question 2

What can the t-test be thought of as?

Answer 2

As the number of standard deviationd that one group mean is different from another

Question 3

What is the chi-squared test used for?

Answer 3

Proportionate outcomes that can be represented by 2x2 contigency tables

• two possible therapies
• two possible outcomes

Question 4

What is the chi-squared test used to assess association between?

Answer 4

Association between the therapy given and the outcome measured

Question 5

Briefly describe hot the chi-squared test is done.

Answer 5

You calculate the expected frequency for each cell if the null hypothesis were true
Compare those expected values with the observed frequencies
If the null hypothesis is true, observed should be close to expected