Sampling techniques

Question 1

Opportunity sampling

Answer 1

recruit those people who are most convenient or most available
advantage - easiest method as you just use the first suitable particpants you can find
disadvantage - biased because the sample is drawn on a small part of the target population

Question 2

Random sampling

Answer 2

• a sample of particpants produced by using a random technique so that every member is tested equally
  advantages - unbiased
  disadvantages - need to have a list of all members of the target population and then contact them - time consuming

Question 3

Snowball sample

Answer 3

• current participants recruit further ones from among people they know
  advantages - enables researcher to locate groups of people who are difficult to access eg drug addicts
  disadvantages - sample is not likely to be a good cross section from the population

Question 4

stratified sampling

Answer 4

• sample of participants produced by identifying subgroups according to their frequency in the target population
  advantages - likely to be more representative than other methods
  disadvantages - very time consuming to identify subgroups and then select subgroups

Question 5

sampling

Answer 5

• the selection of particpants from the sampling frame with the aim of producing a representative selection

Question 6

sampling frame

Answer 6

• the source material from which a sample is drawn

Question 7

target population

Answer 7

• the group of people that the researcher is interested in
• the group of people where a sample is drawn

Question 8

generalisation

Answer 8

applying the findings of a particular study to a target population

Question 9

self selected sampling

Answer 9

a sample where the participants relies solely on volunteers to make up the sample
- advantages : gives access to a variety of participants which may make the sample more representative
disadvantage -sample is biased in other ways because participants are more highly motivated to be helpful

Question 10

systematic sampling

Answer 10

• a sample obtained by selecting every nth person
  advantages : unbiased as participants as selected using an objective system
  disadvantages: not truly unbiased unless you select a number using a random method

Question 11

researcher bias

Answer 11

• anything that an investigator does that has an effect on a participants performance in a study

Question 12

operationalise

Answer 12

ensuring all variables are in a form that can easily be tested
e.g the term educational attainment could be called “GCSE grade in maths”

Question 13

confounding variable

Answer 13

• any variable which varies systemically with the independent variable that might potentially affect that dependent variable