sampling

Question 1

who is the target population

Answer 1

• group of people from whom the sample is drawn
  e. g. if sample of pps is taken from sixth form schools in salisbury the findings can only be applied to that group of people, not all sixth form students in uk or world

Question 2

why do psychologists use sampling techniques

Answer 2

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

Question 3

what is opportunity sampling

Answer 3

• sampling technique used by psychology students
• consists of taking the sample from people who are available at the time of study being carried out and fit criteria you’re looking for

Question 4

advantages of opportunity sampling

Answer 4

ease of formation - quick and practical - uses people who are readily available
natural experiments - has to be used as researcher cannot recruit - researcher has no control over who is studied

Question 5

disadvantages of opportunity sampling

Answer 5

• unrepresentative - cannot be generalised to target population e.g. data collected mid-week in town may not include those who work full-time or are in college
• pps have option to decline so sample may become self-selected

Question 6

what is random sampling

Answer 6

• every member of population has equal chance of being selected
• identifying everyone in 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 hat, computer e.g. random number generator

Question 7

advantages of random sampling

Answer 7

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

Question 8

disadvantages of random sampling

Answer 8

impractical - difficult to achieve to 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 e.g all males/females, all one age

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 population

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 target population

Question 11

disadvantages of stratified sampling

Answer 11

knowledge of of populations 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 “screw you” phenomenon - pps eager to take part so less change of deliberate sabotage
• large number of number of people may respond 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 - eager to please so increases likelihood of demand characteristics

Question 15

what is systematic sampling

Answer 15

taking every nth person from list to create a sample
if company has workforce of 1000 employees and sample of 20 is needed, 1000 ÷ 20 = 50. therefore every 50th name from the list of employees to make a sample

Question 16

advantages of systemic sampling

Answer 16

unbiased - increased chances of representative sample

• generalisation - results are representative of population, unless certain characteristics of population are repeated for every nth person but unlikely
• simple and effective with random element evenly sampled

Question 17

disadvantages of systematic sampling

Answer 17

not representative - does not guarantee unbiased sample e.g. all females
time consuming and list of all of sample needed

Question 18

what societies have the majority of psychological research been on

Answer 18

WEIRD
Western
Educated
Industrialised
Rich
Democratic societies 
thus mostly not representative of whole population