RESEARCH METHODS - sampling

Question 1

what is random sampling

Answer 1

This method gives every member of the target group an equal chance of being selected for the sample (e.g. by assigning a number to each member, and then selecting from the pool at using a random number generator).

Question 2

random sampling weakness

Answer 2

It can be impractical (or not possible) to use a completely random technique, e.g. the target group may be too large to assign numbers to.

Question 3

random sampling strength

Answer 3

sample should represent the target population and eliminate sampling bias

Question 4

stratified sampling

Answer 4

Here the sampler divides or ‘stratifies’ the target group into sections, each showing a key characteristic which should be present in the final sample.
Then each of those sections is sampled individually.
The sample thus created should contain members from each key characteristic in a proportion representative of the target population.

Question 5

stratified sampling strength

Answer 5

highly representative of the target population and therefore we can generalize from the results obtained.

Question 6

stratified sampling weakness

Answer 6

time consuming

Question 7

opportunity sampling

Answer 7

Uses people from target population available at the time and willing to take part. It is based on convenience.

Question 8

opportunity sampling weakness

Answer 8

The consequent sample may not be representative as it could be subject to bias

Question 9

opportunity sampling strength

Answer 9

easy and inexpensive to carry out

Question 10

systematic sampling strength

Answer 10

Assuming the list order has been randomised, this method offers an unbiased chance of gaining a representative sample.

Question 11

systematic sampling

Answer 11

Chooses subjects in a systematic (i.e. orderly / logical) way from the target population, like every nth participant on a list of names.

Question 12

systematic sampling weakness

Answer 12

If the list has been assembled in any other way, bias may be present. For example if every fourth person in the list was male, you would have only males in your sample.

Question 13

volunteer sampling

Answer 13

Here the sample consists of people who have volunteered to be in the study.

Question 14

volunteer sampling strength

Answer 14

This often achieves a large sample size through reaching a wide audience, for example with online advertisements.

Question 15

volunteer sampling weakness

Answer 15

may be unrepresentative sample: those who respond to the call for volunteers may all display similar characteristic