Data Collection

Question 1

Describe census advantages and disadvantages

Answer 1

Measures every member of a population. Accurate result but expensive

Question 2

How to do simple random sampling?

Answer 2

Everyone has same chance of being selected
Use random number/lottery sampling

Question 3

Simple random sampling advs/ disadvs

Answer 3

Bias free, but need sampling frame

Question 4

How to do systematic sampling?

Answer 4

Take every kth unit, k = pop/sample
Pick random number between 1 and k for starting point

Question 5

Systematic sampling advs / disadvs

Answer 5

Quick to use, but need sampling frame

Question 6

How to do stratified sampling?

Answer 6

Sample represents groups (strata) of population. Sample/pop x strata for each strata, pick randomly.

Question 7

Stratified sampling advs/disadvs

Answer 7

Reflects population, but population must be classified in strata

Question 8

How to do quota sampling?

Answer 8

Like stratified, but strata filled by interviewer/researcher

Question 9

Quota sampling advs/disadvs

Answer 9

No sampling frame needed, but non-random so potential bias

Question 10

How to do opportunity sampling?

Answer 10

Quota filled by those available at the time

Question 11

Opportunity sampling advs/disadvs

Answer 11

Easy/cheap, but unlikely to be representative

Question 12

3 data comparisons

Answer 12

Qualitative vs quantitative
Numerical vs non-numerical
Discrete vs continuous