Sampling

Question 1

Who is the target population

Answer 1

• the group of people from whom the sample is draw
• e.g. if the sample of pps is taken from sixth form schools in salisbury, the findings of the study can only be applied to that group of people

Question 2

Why do psychologists use sampling techniques

Answer 2

• to choose poeple who are representative of the population as a whole
• if your sample is representative then you can generalise the results of your study to the wider population

Question 3

What is opportunity sampling

Answer 3

• taking the sample from people who are available at the time the study is carried out, and fit the criteria you are looking for
• most used by psychology students

Question 4

Advantages of opportunity sapling

Answer 4

• quick and practical way of getting a sample

- natural expereiments have to be used as the researcher has no control over who is studied

Question 5

Disadvantages of opportunity sampling

Answer 5

• unrepresentative-cannot be generalised to target population
• pps have the option to decline-so sample may then become self selected

Question 6

What is random sampling

Answer 6

• every member of a population has an equal chance of being chosen
• identifying everyone in the target population and then selecting the number of pps you need in a way that gives everyone in the population an equal chance of being picked
• could be done manually e.g. using a hat, or computer e.g. randomly picking numbers

Question 7

Advantages of random sampling

Answer 7

• unbiased selection-therefore more likely to be representative
• generalisation-if representative then results can be generalised to the target population
• everyone has an equal chance of being selected

Question 8

Disadvantages of random sampling

Answer 8

• impractical-difficult to achieve and get full details of the target population. Not all will be available and some may not want to take part
• not representative-does not guarantee an unbiased sample

Question 9

What is stratified sampling

Answer 9

classifying the population into categories and then choosing a sample which consists of pps from each category in the same proportions as they are in the populatoin

Question 10

Advantages of stratified sampling

Answer 10

• unbiased selection-therefore more likely to be representative
• generalisation-if representative then results can be generalised to the target population

Question 11

Disadvantages of stratified sampling

Answer 11

• knowledge of population characteristics required. May not be available
• time consuming

Question 12

What is self selected (volunteer) sampling

Answer 12

• pps becoming part of a study because they volunteer when asked or in response to an advert
• researcher may then select those suitable for study

Question 13

Advantages of volunteer sampling

Answer 13

• ease of formation-creating sample requires little effort
• less chance of the “screw you” phenomenon-pps are eager to take part so less chance of deliberate sabotage
• large number of people may respons so allows for more in depth analysis and more accurate results

Question 14

Disadvantages of volunteer sampling

Answer 14

• unrepresentative-volunteers tend to be a certain “type” of person so cannot generalise to target population
• demand characteristics-volunteers are eafer to please so increases the chance of demand characteristics

Question 15

What is systematic sampling

Answer 15

• taking the nth person from a list to create a sample
• e.g. if a company has a workforce of 1000 employees and a sample of 20pps is needed, then 1000÷20=50. Therefore take every 50th name from the list of employees to make a sample

Question 16

Advantages of systematic sampling

Answer 16

• unbiased-increases chance of representative sample
• generalisation-the results are representative of the population, unless certain characteristics of the population are repeated for every nth person but this is unlikely
• simple and effective way of generating a sample with a random element-evenly sampled

Question 17

Disadvantages of systematic sampling

Answer 17

• periodic traits-can interact with a hidden periodic trait within a population
• not representative-unbiased selection does not always guarantee an unbaised sample e.g. all females could be selected
• can be difficult to identify traits and characteristics

Question 18

The majority of psychological reserach has been on what kinds of societies

Answer 18

-western
-educated
-industralised
-rich
-industralised
This means most research is not remotely representative of the whole worlds population