Sampling

Question 1

Definition of population

Answer 1

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

Question 2

Definition of sample

Answer 2

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

Question 3

Definition of a target population

Answer 3

A sub-group of the general population

Question 4

Definition of sampling techniques

Answer 4

The method used to select people from the population

Question 5

Definition of bias

Answer 5

In the context of sampling, when certain groups may be over/under represented within the sample selected. This limits the extent to which generalisations can be made to the target audience.

Question 6

Definition of generalisation

Answer 6

The extent to which findings and conclusions from a particular investigation can be broadly applied to a solution. This is made possible if the sample of participants is representative of the whole population

Question 7

What is a random sample?

Answer 7

A sophisticated form of sampling in which all members of the target population have an equal chance of being selected.
Doing this by listing all of the participants names alongside a number, then choose a random number selector or pick a name out of a hat

Question 8

What are the strengths of a random sample?

Answer 8

It is free from researcher bias

it is normally quite representative

Question 9

What are the weaknesses of a random sample?

Answer 9

There is still a chance of obtaining a biased sample

Participants may refuse to take part

Question 10

What is a systematic sample?

Answer 10

When every nth member of the target population is selected. To do this a sampling frame is produced which is a list of people in the target population organised into, for instance, alphabetical order. A sampling system is nominated eg every 3rd, 5th, 7th person etc or the interval may be determined randomly to reduce bias.

Question 11

What are the strengths of systematic sampling?

Answer 11

It is free from researcher bias so long as the nth term hasn’t been chosen to manipulate who is chosen

It is normally quite representative

Question 12

What are the weaknesses of systematic sampling?

Answer 12

There is still a chance of obtaining a biased sample

People may refuse to participate which can lead to a volunteer sample instead

Question 13

What is stratified sampling?

Answer 13

A sophisticated form of sampling in which the composition of the sample reflects the proportions of people in certain sub-groups within the target population or wider population.
This is done by the researcher first identifying the different sub-groups (strata) that make up a population
Then the proportions needed for the sample to be representative are worked out
Finally the participants that make up each stratum are selected using random sampling

Question 14

What are the strengths of stratified sampling?

Answer 14

Avoids researcher bias

Increased representativeness of the population

Question 15

What are the weaknesses of stratified sampling?

Answer 15

The identified strata cannot represent all the ways people are different so complete representation of the target population is not possible

The most time consuming sampling method

Question 16

What is an opportunity sample?

Answer 16

The researcher simply takes the chance to ask whoever’s around in their time of study

Question 17

What are the strengths of an opportunity sample?

Answer 17

It is convenient, it saves the researcher a good deal of time and effort and is extremely less costly in terms of time and money than say, random sampling

Question 18

What are the weaknesses of an opportunity sample?

Answer 18

Suffers from two types of bias, it is unrepresentative of the target population as it is drawn from a very specific area such as one street so fundings cannot be generalised to the target population.
The second is that the researcher has complete control over the selection of participants and therefore may avoid particular people

Question 19

What is a volunteer sample?

Answer 19

Involves participants selecting themselves to be apart of the study, hence why it is also referred to as self-selection
This is done by the researcher placing an advert in a newspaper or notice board.

Question 20

What are the strengths of a volunteer sample?

Answer 20

Requires minimal input from the researcher and so is less time-consuming than any other sampling method
Avoids researcher bias

Question 21

What are the weaknesses of a volunteer sample?

Answer 21

Asking for volunteers may attract a certain type of profile of person, that is one who is helpful, keen and curious, which may then affect the extent to which the findings can be generalised to the population