sampling methods

Question 1

What is random sampling? Strength? Limitation?

Answer 1

-all have an equal chance of being selected e.g names out of a hat
-free from researcher bias, extraneous variables likely to equally divided
-time consuming

Question 2

What is systematic sampling? Strength? Limitation?

Answer 2

-every nth member of the target population is selected and a sampling frame is produced
-avoids researcher bias
-time consuming and expensive

Question 3

What is stratified sampling? Strength? Limitation?

Answer 3

-researcher identifies different groups (stratas) of people that make up the target population and work out the proportion needed from each group for the sample to be representative. Members of each group are then randomly selected
-avoids researcher bias
-not perfect- strata cannot reflect all the ways people are different

Question 4

What is opportunity sampling? Strength? Limitation?

Answer 4

-researcher approaches participant, those willing and available at the time take part
-convenient, easy, cheaper
-researcher bias and may be unrepresentative

Question 5

What is volunteer sampling? Strength? Limitation?

Answer 5

-participant appraoches researcher
-quick and easy
-attracts certain type of people that may be more enthusiastic, may cause bias