Sampling

Question 1

Random sampling

Answer 1

Every member of the population has an equal chance of being selected. So everyone is entered on a list and randomly generated or hand draw.

Question 2

Random sampling evaluation

Answer 2

strengths
- objective due to lack of researcher involvement, less bias
- potentially representative due to laws of chance
weaknesses
- difficult and time consuming as completes list of target population needed

Question 3

Systematic sampling

Answer 3

Selecting every nth number member of the population

Question 4

Systematic sampling evaluation

Answer 4

strengths
- increased objectivity if initial list is randomise - less bias
weaknesses
- Time consuming
- participants may refuse to participate
- each person doesn’t have an equal chance of getting picked
- Could cause unreliability if not a variety of people are picked

Question 5

Stratified sampling

Answer 5

Participants are divided into subgroups called strata based on the characteristics they share. They are all then randomly sampled

Question 6

Stratified sampling evaluation

Answer 6

strengths
- Most likely to lead to a representative sample as it is designed to reflect the population
weaknesses
- Strata can’t reflect all the ways participants are different
- Time consuming due to having to calculate the strata

Question 7

opportunity sampling

Answer 7

Where the researcher selects anyone who is available and willing to participate. These people are still usually a targeted group.

Question 8

Opportunity sampling evaluation

Answer 8

strengths
- Quick and convenient as participants are readily available
- reduces time and cost
weaknesses
- unrepresentative samples as it is drawn rom one physical area
- subject to researcher bias as they are in control of selection

Question 9

Volunteer sampling

Answer 9

Participants self select to be part of the study. so they could respond to an advertisement, a questionnaire etc.

Question 10

Volunteer sampling evaluation

Answer 10

strengths
- Convenient method as minimal input is needed from the researcher and so is less time consuming
- Less chance of attrition as participants have volunteered
weaknesses
- volunteer bias is likely as there is a certain profile of a volunteer
- more subject to demand characteristics