sampling

Question 1

sample

Answer 1

the group of people who take part in the investigation - the sample is drawn from a target population

Question 2

target population

Answer 2

a group of people who are the focus of the researcher’s interest, from which a smaller sample is drawn

Question 3

sampling method

Answer 3

the method used to select people from the population

Question 4

random sampling

Answer 4

all members of the target population have an equal chance of being selected

Question 5

systematic sampling

Answer 5

every nth member of the target population is selected

Question 6

stratified sampling

Answer 6

composition of the sample reflects the proportions of people in certain sub-groups (strata) within the target population

Question 7

opportunity sampling

Answer 7

researchers select anyone who is willing and available to be part of the sample

Question 8

volunteer sampling

Answer 8

participants select themselves to be part of the sample, self-selection

Question 9

random sampling example

Answer 9

a researcher obtains a list of all the names of people in a target population
they then assign each name a number
finally, they use a random number generator to select their required sample

Question 10

systematic sampling example

Answer 10

a sampling frame is produced, list of people in target population organised into alphabetical order for example

interval is chosen eg 2nd 8th this may be determined randomly in order to reduce bias

researcher works through sampling frame until complete

Question 11

stratified sampling example

Answer 11

identify strata that makes up the population

the proportions needed for the sample to be representative need to be calculated

finally, the participants that make up the stratum are selected using random sampling

Question 12

opportunity sampling example

Answer 12

the researcher simply asks those who are around at the time of the study

Question 13

volunteer sampling

Answer 13

a researcher may place an advert on a notice board, or in a newspaper

Question 14

random sampling strengths

Answer 14

this is free from researcher bias as the researcher has no influence over who is selected

fair representative sample as participants are chosen at random

Question 15

random sampling limitations

Answer 15

a less practical method of sampling, it is time-consuming to complete and it is hard to obtain as selected participants may refuse to take part

Question 16

systematic sampling strengths

Answer 16

this avoids researcher bias, once the sampling system is nominated the researcher has no influence

fairly representative sample as participants chosen using a sampling frame

Question 17

systematic sampling limitations

Answer 17

this is a less practical method of sampling; it is time-consuming to complete and it is hard to obtain as selected participants may refuse to take part

Question 18

opportunity sampling strengths

Answer 18

this is a more practical method of sampling, as it is much easier to obtain a sample if you just select those willing and available

Question 19

opportunity sampling limitations

Answer 19

there is a problem of researcher bias as the researcher has complete control over the selection process

the sample is unrepresentative of the total population as it is usually drawn from a specific area

Question 20

volunteer sampling strengths

Answer 20

this is a more practical method of sampling, as participants volunteer therefore are not going to refuse

Question 21

volunteer sampling limitations

Answer 21

there is a problem of volunteer bias asking for volunteers may attract a certain type of person

the sample is unrepresentative of the total population as only certain types of people volunteer for studies

Question 22

researcher bias

Answer 22

in the context of sampling, this is when the researcher’s opinions influence the way in which they select their participants

Question 23

generalisation

Answer 23

this is the extent to which findings and conclusion from a particular investigation can be applied to the population. This is made possible if the sample is representative of the population