Applied Economics & Statistics: Topic 4 - Sampling Methods and the Central Limit Theorem

Question 1

Describe & explain ‘sampling’

Include definition

Answer 1

• Sampling - a process of selecting items from a population
• Samples are selected by specific techniques that attempt to ensure the
  sample is representative of the population.
• We want to generalise from the sample to the population, and to allow
  for the use of inferential techniques. I.e, infer, from our sample results, information about the population.
• So samples need to be representative.
• More likely if every member of the population has equal probability of
  being selected.
• Larger sample better than small.

Question 2

What’s the name for ‘a process of selecting items from a population’?

Answer 2

Sampling

Question 3

List why samples are used

Answer 3

• To save time.
• To save money.
• To improve feasibility.
• The destructive nature of some tests

Question 4

State the important concepts in inferential statistics

Answer 4

• Important concepts in inferential statistics:
  1. Probability sampling.
  2. Sampling distribution (a theoretical distribution that links sample to
  population)

Question 5

What’s a ‘probability sample’?

Answer 5

A sample selected such that each item or person in the population being studied has a known likelihood of being included in the sample

Question 6

What’s the name for ‘a sample selected such that each item or person in the population being
studied has a known likelihood of being included in the sample’?

Answer 6

Probability Sample

Question 7

What are the four methods in which we can construct a probability sample?

Answer 7

1. Simple random sampling.
2. Systematic random sampling.
3. Stratified random sampling.
4. Cluster sampling

Question 8

What’s ‘simple random sampling’?

Answer 8

Sample selected so that each item or person in the population has the
same probability of being included. example: include one example from 1 of the following: do a random draw, or use random number generators to choose the
sample