Research Methods: Selecting and Using Participants

Question 1

What is the target group

Answer 1

The part of the population that you’re interested in studying

Question 2

What is the sample and why do you take one

Answer 2

You can’t include everyone in the target group, so you choose a sample of ppts
The sample should be representative (should reflect the variety of characteristics that are found in the target group) so that the results can be generalised to the whole target group

Question 3

What is a sample that is unrepresentative

Answer 3

It is biased and can’t be reliably generalised to the whole target group

Question 4

What is random sampling

Answer 4

When everyone in the target group has an equal chance of being selected
Can be done using names in a hat or a computer could randomly pick numbers assigned to ppts

Question 5

Advantages of random sampling

Answer 5

Fair
Everyone has an equal chance of being selected
Likely to be representative

Question 6

Disadvantages of random sampling

Answer 6

Doesn’t guarantee a representative sample - still a chance some subgroups may not be selected
If the target group is large then it may not be practical or possible give everyone a number

Question 7

What is opportunity sampling

Answer 7

When the researcher samples whoever is available and willing to be studied

Question 8

Advantages of opportunity sampling

Answer 8

Quick and practical way of getting a sample

Question 9

Disadvantages of opportunity sampling

Answer 9

Unlikely to be representative of the target group or population as a whole
So findings can’t be confidently generalised

Question 10

What is volunteer sampling

Answer 10

When people actively volunteer to be in a study by responding to a request for ppts advertised by the researcher e.g. in a newspaper
Researcher may then select only those who are suitable for the study

Question 11

Advantages of volunteer sampling

Answer 11

If an advert is placed prominently (e.g. a national newspaper) a large number of people may respond, giving more ppts to study
This may allow more in-depth analysis and more accurate statistical results

Question 12

Disadvantages of volunteer sampling

Answer 12

A large amount of people may respond to the study, but these only include people who saw the advertisement, other people would not have a chance of being selected
People who volunteer may be more cooperative than others, so the sample is unlikely to be representative of the target population

Question 13

What is systematic sampling

Answer 13

Where every nth name from a sampling frame (record of all names in a population) is taken
E.g. every 3rd name from a register

Question 14

Advantages of systematic sampling

Answer 14

Simple and effective way of generating a sample with a random element
Means that the population is more likely to be evenly sampled than by using opportunity or volunteer samples

Question 15

Disadvantages of systematic sampling

Answer 15

Subgroups might be missed
Will not be representative if the pattern used for the samples coincides with a pattern in the population

Question 16

What is stratified sampling

Answer 16

Where all the important subgroups in the population (e.g. different age or ethnic groups) are identified and a proportionate number of each is randomly obtained

Question 17

How to carry out a stratified sample

Answer 17

Class of 20 students:
Ten are 16 years old
Eight are 17 years old
Two are 18 years old
A stratified sample of 10 students, the numbers of the different ages must equal 50% of the class, you will need:
Five 16 year olds
Four 17 year olds
One 18 year olds

Question 18

Advantages of stratified sampling

Answer 18

Can produce a fairly representative sample
Can also be used with random and systematic sampling

Question 19

Disadvantages of stratified sampling

Answer 19

Can take a lot of time and money to do it
Some subgroups may be missed
Can be difficult to identify traits and characteristics (such as people’s ages or backgrounds) effectively enough to stratify the sample properly

Question 20

What is the Hawthorne effect

Answer 20

If people are interested in something and in the attention they are getting (e.g. from researchers), then they show a more positive response, try harder in tasks, and so on
This means results are artificially high which could make conclusions invalid
Opposite effect may occur if the ppts are uninterested in the task
(Please you or screw you effect)

Question 21

What are demand characteristics

Answer 21

There are aspects of a study, which allow the ppts to form an idea about its purpose
If they think they know kind of response the researcher is expecting from them, they may show the response to ‘please’ the researcher (or more deliberately do the opposite)
This would make the conclusions invalid

Question 22

What is social desirability bias

Answer 22

People usually try to show themselves in the best possible light
In a survey, they may not be completely truthful, but the give answers that are more socially acceptable instead
This would make the results less valid

Question 23

What is researcher/ experimenter bias

Answer 23

The researchers’ expectations can influence how they design their study and how they behave towards the ppts
Their expectations can influence how they take measurements and analyse their data, resulting in errors that can lead, e.g. to accepting a hypothesis that was actually false
Their expectations may also lead them to only ask questions about what they are interested in, and they may focus on the aspects of the ppts answer which fit their expectations

Question 24

Investigator effects

Answer 24

These can be anything that the researcher does which can affect how the ppt behaves
If a researcher’s expectations influence how they behave towards their ppts, the ppts might respond to demand characteristics
Also, a researcher’s expectations could result in them asking leading questions
Finally, the ppt may react to the behaviour or appearance of an investigator and answer differently