Research Methods - Sampling Techniques

Question 1

Target population

Answer 1

• group researchers are studying and want to generalise their results to

Question 2

What are sampling techniques used for?

Answer 2

• obtain sample of target population = avoid studying entire population = long + expensive

Question 3

Sample

Answer 3

• should be representative of the population
• should have same characteristics as population

Question 4

Random sampling

Answer 4

• every member of target population has the same chance of being selected
  E.g. random name generator

Question 5

Random sampling adv = large

Answer 5

• if target population is large + large sample is drawn = likely sample is representative = results can be generalised to the target population

Question 6

Random sampling adv = bias

Answer 6

• no researcher bias selecting the sample
• sample chosen by chance = no conscious choice from researcher
• equal chance for everyone

Question 7

Random sampling dis = difficult

Answer 7

• sometimes difficult to get full details of a target population from which to select a sample
  E,g,not possible to get a full list of all women in the uk

Question 8

Random sampling did = willing

Answer 8

• not all members of target population who are selected will be available or willing to take part = unrepresentative sample
• sample size reduced if people refuse to take part

Question 9

Systematic sampling

Answer 9

• participants are selected by taking every Nth person from a list

Question 10

Systematic sampling adv

Answer 10

• simpler than random sampling = only requires a list of the target population + researcher decides to select every nth person.
• less effort

Question 11

Systematic sampling dis = hidden periodic trait

Answer 11

• process of selection can interact with a hidden periodic trait within the population = not representative

Question 12

Systematic sampling dis = willing

Answer 12

• not all members of target population who are selected will be available or willing to take part = unrepresentative sample
• sample size reduced if people refuse to take part

Question 13

Stratified sampling

Answer 13

• classifying population into categories + randomly choosing sample that consists of participants from each category in the same proportions as they are in the population
• representative sample

Question 14

Stratified sampling adv

Answer 14

all groups within a population are included = representative

Question 15

Stratified sampling dis

Answer 15

• very time consuming = categories have to be identified and calculated
• struggle if you don’t have all the details of people in your target population

Question 16

Opportunity sampling

Answer 16

• ## selecting participants who are readily available and willing to take part = convenience sampling

Psychologists might have easy access to a group of people that they know well or have regular contact with. It might therefore be convenient to approach these people to ask them to take part in their research.

Question 17

Opportunity samplig adv

Answer 17

• easiest + most practical method of ensuring large samples

Question 18

Opportunity sampling dis

Answer 18

• high chance sample isn’t representative
• people may feel obliged to take part in research even if they don’t want to = unethical

Question 19

Volunteer sampling

Answer 19

• people volunteer to participate in study
• researcher will usually advertise for people to take part e.g. leaflets, posters, radio or tv broadcasts
  -people take notice of the information and can then decide if they would like to take part in the research and volunteer their time.

Question 20

Volunteer sampling adv

Answer 20

• saves research time + effort
• researcher only makes advertisements then waits for participants to come to them + volunteer time and involvement

Question 21

Volunteer sampling disadv

Answer 21

• certain people volunteer (enthusiastic, interested in topic) = high chance of unrepresentative sample that doesn’t reflect target population

Question 22

What is a pilot study?

Answer 22

-initial run-through of the procedures to be used in an investigation; it involves selecting a few people and trying out the study on them

Question 23

What do you save with a pilot study?

Answer 23

Time, money

Question 24

How do pilot studies help?

Answer 24

• help spot any ambiguities or confusing in the information given to participants or problems with the task devised

Question 25

Floor effect pilot study

Answer 25

- task is too hard - none of the participants can score at all or can complete the task – all performances are low.

Question 26

Ceiling effect pilot study

Answer 26

task is so easy that all achieve virtually full marks or top performances

Question 27

When using self-report measures it is important to check as part of the pilot study

Answer 27

The participants understand the questions and are prepared to answer them That closed questions offer suitable options Whether open questions are also needed to elicit unpredictable responses Whether the reporting method is appropriate, e.g. if a face-to-face interview is too intimidating should it be changed to a questionnaire?

Question 28

In observations it is important to check

Answer 28

Observers agree on operational definitions of behavioural categories Inter-observer reliability – do the researchers need practice observing the behaviours? The behavioural categories include all the important behaviours The behavioural categories do not overlap Whether the participants are affected by the observers – should they be covert?