Sampling Methods

Question 1

self selecting sampling

Answer 1

Also known as a volunteer sample. People that sign-up are usually motivated and are less likely to drop out of the research. However, that may lead to a sample that is not representative of the target population.

Question 2

opportunity sampling

Answer 2

Also known as a convenience sample. This is when you use a pre-existing sample - for example, Mr. Smith’s grade 9 English class.
It is an easy way to get participants because they are readily available.
The groupings often tend to be relatively homogeneous. However, they are also not usually representative of a target population.
However, if you were doing a study only on grade 9 students at your school, and you used four out of the five existing English classes, then your study would be fairly representative.

Question 3

RANDOM SAMPLING

Answer 3

A random sample is defined as a sample in which everyone in the target population had the same probability of being chosen.
This is often seen as an ideal sampling technique, but if the target population is too large, then random sampling is not really possible. In addition, if the target population is very heterogeneous, then random sampling could still generate a biased sample.

Question 4

Random allocation

Answer 4

Random allocation is how I decide which group or condition a participant will be in.

Question 5

Purposive sampling

Answer 5

A purposive sample is looking for people with a very specific set of traits.
This could be African-American women between 30 and 40 years old or expatriates who have lived in Prague for at least 25 years.
This is often accomplished by a self-selected sample

Question 6

snowball sampling

Answer 6

Also known as a network sample.
This is another type of purposive sampling, but network sampling is used when you are looking for participants from a specific group that would not respond to an ad in a paper.
For example, former drug addicts, people engaged in illegal activities, or victims of domestic violence.
It could also be because you think that a participant could help you find people more efficiently.
For example, if you are looking for expatriates who have been in Prague for at least 25 years. If you find a few, they may have friends that could help with the research.
Network sampling also helps to build trust with the researcher. If a recovered drug addict recommends my research to a friend with the same history, it saves time in trying to build up trust for carrying out the research. If John thought the researcher was ok, then so does his friend

Question 7

stratified sampling

Answer 7

Stratified sampling attempts to make a sample that reflects the sub-groups within a target population.

Question 8

problem with stratified sampling

Answer 8

The problem with stratified samples is that we have to be careful about how they label the groups within a community.