Sampling Techniques

Question 1

What is a population and why is this entire group not used as a sample

Answer 1

Group of people who are the focus of the researcher’s interest from which a smaller sample is drawn , not practical or economically viable to include whole target population

Question 2

What is the target population

Answer 2

The specific group the researcher is interested in studying

Question 3

What is a sample

Answer 3

The group of people who take part in a research investigation, drawn from the target population and is presumed to be representative of that so findings can be generalised

Question 4

What is random sampling and how is this done

Answer 4

All members of the target population have an equal chance of being selected
-get complete list of all members of target population and all names are assigned a number, sample generated via lottery method(random number generator/numbers out of a hat)

Question 5

Strengths of random sampling

Answer 5

-free from researcher bias as they have no influence over who is selected

Question 6

Limitations of random sampling

Answer 6

-may be difficult and time consuming to get complete list of all members of target population
-sample may still be unrepresentative of target population

Question 7

What is systematic sampling and how is this done

Answer 7

-method in which every nth member of a target population is selected
-done by producing a sampling frame(list of all in target population organised into eg alphabetical order), sampling system then nominated and work through frame

Question 8

Advantages of systematic sampling

Answer 8

-avoids researcher bias as once sampling system has been chosen the researcher has no influence over who makes up the sample
-usually representative=findings can be generalised

Question 9

Limitations of systematic sampling

Answer 9

-can still not be representative
-time consuming to obtain list of whole target population=effort for the researcher

Question 10

What is stratified sampling and how is it done

Answer 10

Method in which the composition of the sample reflects the proportions of people in certain subgroups within the target population
-done by first identifying the dif strata that make up the population and then calculating the proportions needed for the sample to be representative, then pps from each strata selecting using random sampling and randomly assigned to conditions

Question 11

Advantages of stratified sampling

Answer 11

-avoids researcher bias as pps randomly selected
-produces a representative sample as it is designed to reflect population=can generalise findings

Question 12

Limitations of stratified sampling

Answer 12

-identified strata cannot reflect all the ways in which people are different
-time consuming and requires a lot of effort

Question 13

What is opportunity sampling

Answer 13

Method in which researchers select anyone who happens to be willing and available to be part of the sample

Question 14

Advantages of opportunity sampling

Answer 14

-convenient as saves time and effort

Question 15

Limitations of opportunity sampling

Answer 15

-sample likely to be unrepresentative as drawn from very specific area(means pps likely to share similar characteristics)=cannot generalise
-researcher bias, may be drawn to certain people over others

Question 16

What is volunteer sampling and how is this done

Answer 16

-participants select themselves to be part of the sample(self-selection)
-done by placing advert and waiting for responses

Question 17

Advantages of volunteer sampling

Answer 17

• low effort and less time consuming as participants come to the researcher

Question 18

Limitations of volunteer sampling

Answer 18

-volunteer bias: adverts likely to only attract a certain profile of person meaning sample unlikely to be representative