INTRODUCTION TO ESTIMATING HOW MANY PARTICIPANTS ARE NEEDED 27/10/16

Question 1

What is estimations?

Answer 1

finding an estimate of some variable of interest

Question 2

Where do you estimate from and where do you extrapolate this to?

Answer 2

study sample and extrapolate this to your target population

Question 3

How can estimates be measured? (2)

Answer 3

1. means

2. frequencies

Question 4

How do you measure the level of uncertainty in your estimate? (2)

Answer 4

• confidence interval

- standard error

Question 5

What is hypothesis testing?

Answer 5

formal statiscal testing of a hypothesis

Question 6

What is a null hypothesis?

Answer 6

no effect

Question 7

what is an alternative hypothesis?

Answer 7

effect

Question 8

How do medical studies test the hypothesis?

Answer 8

whether some average value differs from zero

Question 9

How do we formally test hypotheses?

Answer 9

by calculating how likely our observations are under the null hypothesis

Question 10

How is probability measured?

Answer 10

p value

null hypothesis is p<0.05

something being significantly different from the null hypothesis