Sample Surveys

Question 1

Bias

Answer 1

“Deviations from a pure random sample”

Question 2

Picking a sample with the probability method

Answer 2

• the interviewer is not involved in the selection
• the method of selection is impartial
• the interviewer can compute the chance of any particular individuals being chosen. i.e. there is a defined procedure for selecting the sample, which uses chance and can be considered objective

Question 3

Simple random sampling

Answer 3

drawing individuals randomly without replacement.
* 1st individual sampled with prob 1/N
* 2nd individual sampled with prob 1/(N-1) etc.

Question 4

Multi-stage cluster sampling

Answer 4

a probability sampling technique which takes samples in stages, and individuals or clusters are chosen at random at each stage

Question 5

Parameter estimate =

Answer 5

true parameter + bias + chance error

Question 6

Bias is the difference between what you want to estimate and what your method is estimating

Answer 6

If the difference is non-zero, that is the bias