Research Methods: Sampling

Question 1

Definition of population

Answer 1

-Refers to a group of people who are the focus of the researcher’s interest.

Question 2

What is a sample?

Answer 2

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

Question 3

What are samples used for?

Answer 3

-Samples are used for both practical and economic reasons as it is usually not possible to include all members of a target population in an investigation so a researcher selects a smaller group.
-Ideally, the sample will be representative of the target population so that generalisation of findings becomes possible.
-However, this may not be possible so bias may happen.

Question 4

What is sampling technique?

Answer 4

-When we use a sample of people, we need to decide how we are going to gather these participants.
-This method used to select people is known as a sampling technique.
-The researcher should choose a sampling technique which is practical and economically viable, however, their main aim should be to produce a representative sample.

Question 5

How many sampling techniques are there?

Answer 5

5

Question 6

What are the 5 sampling techniques?

Answer 6

1.Opportunity Sampling
2.Random Sampling
3.Stratified Sampling
4.Systematic Sampling
5.Volunteer Sampling

Question 7

What opportunity sampling?

Answer 7

-Opportunity sampling selects participants based on who is available at the time of the study and willing to take part.
-This sampling is very common in market research .e.g. a shop asks customers.

Question 8

What is random sampling?

Answer 8

-Random sampling is a technique where every member of the target population has an equal chance of being selected.
-This type of sampling is most commonly associated with large-scale surveys and scientific research.
-For example, a researcher puts all student names from a school into a hat and picks 30 at random to take part in a survey.

Question 9

What is stratified sampling?

Answer 9

-Stratified sampling divides the population subgroups (strata) based on relevant characteristics (.e.g. age, gender), and participants are randomly selected from each subgroup in proportion to their size in the population.

Question 10

What is systematic sampling?

Answer 10

-Systematic sampling is when you select participants using a fixed, regular interval from a list of the population, after choosing a random starting point.
-Thus is most commonly used in large-scale surveys and structured research studies where a full list of the population is available.-.e.g. government researcher academic studies.

Question 11

What is volunteer sampling?

Answer 11

-Volunteer sampling occurs when participants choose to take part in a study, usually by responding to an invitation or advertisement.
-Thus type of sampling is associated with studies that require quick and easy recruitment, like online surveys.
-For example, a study advertises for participants on a university notice board, and students who are interested volunteer to participate.

Question 12

Strengths of Opportunity Sampling (2)

Answer 12

1.Quick,easy, and convenient to use (saves time and effort)
2.Useful when conducting research in natural settings-requires minimal preparation or planning

Question 13

Strengths of Random Sampling (3)

Answer 13

1.Reduces researcher bias (each member has an equal chance)
2.Produces a more chance representative sample than opportunity or volunteer methods
3.Easy to analyse statistically (each participant has known probabilities of selection)

Question 14

Strengths of Stratified Sampling (3)

Answer 14

1.Ensures all subgroups (strata) of the population are fairly represented
2.Produces one of the most representative samples.
3.Reduces sampling bias compared to opportunity or volunteer methods.

Question 15

Strengths of Systematic Sampling (3)

Answer 15

1.Simple and efficient once a population list is available.
2.Objective and less open to researcher bias (uses a set rule).
3.Provides a more structured and representative approach than opportunity sampling.

Question 16

Strengths of Volunteer Sampling (3)

Answer 16

1.Easy to recruit (participants self-select).
2.Can reach a large audience via adverts or online postings.
3.Useful for obtaining participants quickly, especially for specialised topics.

Question 17

Weaknesses of Opportunity Sampling (2)

Answer 17

1.Highly biased and often unrepresentative of the wider population.
2.Researcher bias may influence who is approached or selected-Findings may lack population validity.

Question 18

Weaknesses of Random Sampling (3)

Answer 18

1.Time-consuming and difficult to achieve in practice.
2.Requires a complete list of the target population (often unavailable).
3.Participants selected may still refuse to take part, reducing representativeness.

Question 19

Weaknesses of Stratified Sampling (3)

Answer 19

1.Very time-consuming to identify and divide subgroups.
2.Requires detailed knowledge of the population’s characteristics.
3.Difficult to implement correctly;still possible to introduce bias within strata.

Question 20

Weaknesses of Systematic Sampling (3)

Answer 20

1.Not truly random if the list has an underlying pattern (periodicity).
2.May lead to bias if the order of names corresponds to certain characteristics.
3.Requires an ordered list of the population.

Question 21

Weaknesses of Volunteering Sampling (3)

Answer 21

1.Volunteer bias:participants may be more motivated,confident,or have specific interests.
2.Sample often unrepresentative of the wider population.
3.Findings may lack population validity due to self-selection.