Collecting and Analysing data

Question 1

What is a quasi-experiment or natural experiment?

Answer 1

An experiment which has a source of randomisation that is as if it were randomly assigned, but this variation was not a result of an explicit randomised treatment and control design

Question 2

What is program evaluation?

Answer 2

The field of statistics aimed at evaluating the effect of a program or policy

Question 3

What is statistical significance?

Answer 3

When a relationship between 2 or more variables is unlikely due to chance, given the assumptions made about the variables. It does not tell us whether there is a causal link

Question 4

Describe Hypothesis Testing?

Answer 4

• Formulate a null hypothesis and an alternative hypothesis

- If the p-value is smaller than the significance level reject the null hypothesis, if not don’t reject it

Question 5

What is the p-value?

Answer 5

The probability of observing the data collected

Question 6

What is the significance level?

Answer 6

A cut-off probability that determines whether a p-value is considered statistically significant. If a p-value is smaller than the significance level, it is considered unlikely that the differences observed are due to chance

Question 7

What is a Type 1-error?

Answer 7

When the null hypothesis is rejected when it was in fact true

Question 8

What is the probability of making a Type 1-error?

Answer 8

The significance level

Question 9

Give 3 main limitations of lab experiments

Answer 9

• Individuals behave differently when they know they’re anonymous
• Lab experiments isolate the effect of one variable by keeping others constant
• Individuals with certain characteristics select themselves into experiments so they may not be representative of the whole population