sampling

Question 1

population

Answer 1

a group of people who are the focus of the researchers interest from which a smaller sample is drawn

Question 2

target population

Answer 2

sub set of the original population

Question 3

what should samples be representative of

Answer 3

target population so that generalisabilty becomes easier

Question 4

what occurs when the diverse nature of populations are not in the sample

Answer 4

bias

Question 5

sample

Answer 5

a small group of people who take part in a research investigation. the sample is drawn from the target population and is presumed to be a representative of that population

Question 6

random sample

Answer 6

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

Question 7

how do you carry out a random sample

Answer 7

a list of all members of the population should be obtained. the names on the list are assigned a number. the sample is selected through the use if a lottery method

Question 8

stratified sample

Answer 8

sophisticated form of sampling where the composition of the sample reflects the proportions of the people in certain subgroups within the target or wider population

Question 9

how do you carry out a stratified sample

Answer 9

the strata (subgroups) of the population. then, the proportions of the sample need to be representative are worked out. the participants that make up each strata are selected using random sampling

Question 10

opportunity sample

Answer 10

researchers take on anyone who happens to be willing and available. the researcher would simply take the chance and ask anyone who is around at the time of the study, for example on the street

Question 11

random sample strengths

Answer 11

-potentially unbiased as confounding or extraneous variables should be equally divides between the different groups, enhancing internal validity

Question 12

random sampling limitations

Answer 12

-difficult and time consuming to conduct as complete list of target population is difficult to obtain
-sample may be unrepersentative
-selected participants may refuse to take part which could result in sample being more like a volunteer sample

Question 13

systematic sample strengths

Answer 13

-objective. once the system for selection is established the researcher has no influence over who is chosen

Question 14

systematic sampling limitations

Answer 14

-method is time consuming and participants may refuse to take part, resulting in a volunteer sample

Question 15

stratified sample strengths

Answer 15

-produces a representative sample because it is designed of accurately reflect the composition of the population. this means that generalisation of findings is possible

Question 16

opportunity sample strengths

Answer 16

-convenient as is much less costly in terms of time and money as list of target population is not required so there is no need to divide population into different strata such as in stratified sampling

Question 17

opportunity sample limitations

Answer 17

-suffers from two forms of bias
-the first form of bias is the sample is unrepresentative of the target population as it is drawn from a very specific area such as one street, so findings cannot be generalised to the target population
-second form of bias is the researcher has complete control over the selection of participants and may be able to avoid certain people –> researcher bias

Question 18

volunteer sample strengths

Answer 18

-collecting a volunteer sample is easy and it requires minimal input from the researcher and so is less time consuming

Question 19

volunteer sample limitations

Answer 19

-volunteer bias is a problem as asking for volunteers may notice a certain profile of person that is curious and more likely to try and please the researcher –> affects how findings can be generalised