1-3

Question 1

What is a population?

Answer 1

• Entire set of items in the group being studies

Question 2

What is the Census and advantages and disadvantages?

Answer 2

• Measuring every member of a population
  + accurate
• • Expensive some testing destroys the items

Question 3

What is the sampling frame?

Answer 3

List of sampling units

Question 4

What is simple random sampling + and -?

Answer 4

Equal chance of being selected, use random generator alongside sampling frame
+ bias free
- sampling frame required

Question 5

What is systematic sampling + and -?

Answer 5

• Takes every kth unit and picks a random number between 1 and k for start point
  + Quick to use
• Sampling frame required

Question 6

What is stratified sampling + - ?

Answer 6

Proportionally represents groups in the sample to reflect population, use either simple random or systematic to fill groups
+ reflect popultaion
= need clear strata for population

Question 7

What is opportunity sampling + and -?

Answer 7

• Sample based on who/what is available
  + easy and cheap
• Unlikely to be represnetitive

Question 8

What is quota sampling + and -?

Answer 8

starts with quotas to be filled, but not necessarily rep of population. Groups filled using opportunity sampling
+ No sample frame needed
- Not random and potential bias

Question 9

Explain the different data types?

Answer 9

Qualitative: Non numerical data
Quantitive: Numerical
Discrete: Can only take certain values
Continuous: Any value in range must be grouped