Sampling methods

Question 1

opportunity sampling

Answer 1

• Includes anyone who is available and willing to participate at that time.
• For example, selecting the first person to walk past a doorway.

Question 2

advantage of opportunity sampling

Answer 2

• easy and available for anyone to do
• does not include a lengthy process to locate the participants therefore it is time efficient.

Question 3

disadvantage of opportunity sampling

Answer 3

• Much more susceptible to bias which means that it is an unrepresentative sample and is harder to generalise.
• excludes a larger portion of the target population.

Question 4

Random sampling

Answer 4

• gives everyone the same chance of being selected
• computer programme or pick names out of a hat

Question 5

advantage of random sampling

Answer 5

• unbiased because everyone has the same chance of being selected and can therefore be generalised for the whole population.

Question 6

disadvantage of random sampling

Answer 6

• relies on the participants availability, if they have to use someone else instead then it wouldn’t be random.
• could be biased (all girls, all same age).

Question 7

systematic sampling

Answer 7

• chooses participants from the target population in a systematic way.
• putting names in alphabetic order and choosing the nth name.
• or/ divide the total number of the population with the sample size to obtain the sampling fraction.

Question 8

advantage of systematic sampling

Answer 8

• the sample will be representative of the total population because the system is objective and can therefor be generalised.

Question 9

disadvantage of systematic sampling

Answer 9

-time consuming.
- has to be selected randomly in order for the results to be reliable.

Question 10

self-selected/volunteer sampling

Answer 10

• participants select themselves.
• advertisements in posters, newspapers and magazines

Question 11

advantage of volunteer/ self-selected sampling

Answer 11

• easy and convenient for the researcher as they only have to advertise it and nothing else
• generally less biased than opportunity sampling as it gives everyone the opportunity to respond
• allows the researcher to target very specific samples in relation to a population

Question 12

Disadvantage of self-selected/volunteer sampling

Answer 12

• chance that volunteer isn’t a typical member of the target population
• placing of advertisement may influence type of participants being used
• may be time consuming having to wait for enough participants to sign up

Question 13

Snowball sampling

Answer 13

• used when it is difficult to locate members of a target group (small target group, hidden identities)
• researcher identifies a participant and the ask them to refer or nominate other potential participants

Question 14

Advantages to snowball sampling

Answer 14

• allows researchers to study issues or topics which may be unavailable through other methods

Question 15

disadvantages to snowball sampling

Answer 15

• More likely to be biased as it relies on peoples connection, may not get a representative sample of the target group

Question 16

Stratified sampling

Answer 16

• Identifying the different groups of people in the target group and randomly selecting participants from each group based on the frequency of occurrence in the general population

Question 17

advantages to stratified sampling

Answer 17

• highly representative sample because the frequency of certain types of people is equal to their frequency in our target population

Question 18

disadvantage to stratified sampling

Answer 18

• very time consuming as it involves a lot of working out

Question 19

Quota sampling

Question 20

Advantages of quota sampling

Answer 20

• sample still has a good chance of being representative of the general population because the rate of occurrence is still the same

Question 21

disadvantage of quota sampling

Answer 21

• sample could be biased as they are only using sections of the target population

Question 22

time sampling

Answer 22

making observations for short intervals within a period of time- more detailed

Question 23

event sampling

Answer 23

all behaviours recorded each time they occur- less detailed