Sampling

Question 1

Sampling

Definition A01

Answer 1

-Process of selecting a representative group from the population
-‘Sample’ is a group of people taking part in an investigation
-‘Target population’ is the total individuals from which a sample might be drawn
-Purpose= to learn about large groups of people, who have something in common- target population
-Sometimes this is as broad as ‘all humans’ but also may be a smaller group eg teenagers
-It is impossible to study everyone within the target population= psychologists select a sample/subgroup which are likely to be representative of the target population of interest
-We want to generalise from the sample to the target population, the more representative a sample is the more confident a researcher can be that their results can be generalised to the target population
-Issues= Sample bias
Situations where the sample doesn’t reflect the characteristics of the target population eg uni students

Question 2

Sampling

Random sampling A01

Answer 2

Random sampling-
A type of probability sampling where everyone in the entire target population has an equal chance of being selected.
-Requires a way of naming/numbering the target population, using some type of raffle method to choose those to makeup the sample
-Considered the best method of selecting your sample from population of interest; little chance of sample bias

Question 3

Sampling

Stratified sampling A01

Answer 3

Stratified sampling-
The researcher identifies the different types of people which makeup up the target population and works out the proportions needed for the sample to be representative
-List is made of each variable which might have an effect on the research
-Have to workout the relative percentage of each group; the sample must then contain all these groups in the same proportion as in the target population

Question 4

Sampling

Volunteer sample A01

Answer 4

Volunteer sample-

Consists of volunteers offering to be apart of the study

Question 5

Sampling

Opportunity sampling A01

Answer 5

Opportunity sampling-
Uses people available at the time to be apart of the study from target population
-Willing to take part
-Based on convenience

Question 6

Sampling

Evaluation- random A03

Answer 6

Strength- Random sampling is considered the fairest way to obtain a unbiased sample as everyone in the population has the same chance of being picked. There is no chance for the researcher to hand pick the ‘perfect’ participant. Therefore, studies which use this sampling method will have higher validity regarding the sample

Weakness- There are practical issues with this sampling method, the larger the target population is the harder it is to gain access to them all. Therefore, some kind of raffle to choose participants may not only be time consuming but somewhat improbable. Showing the use of this method to be limited

Question 7

Sampling

Evaluation- Stratified A03

Answer 7

Strength-
This method provides a sample very representative of the target population as all sub groups are part of the sample of the study. Therefore the results of the study are easily generalisable and likely to be highly valid in measuring the behaviour of the target population.

Weakness-
However, this method requires the additional process of identifying sub groups and variables which makes the method time consuming. Therefore, the practicalities of this sampling method may not be useful for all studies, limiting its use as a method.

Question 8

Sampling

Evaluation- Opportunity A03

Answer 8

Strength-
Opportunity sampling utilises those participants at the time and therefore highly convent and time efficient. This can be useful for studies with time constraints or limited resources

Weakness-
However, with opportunity sampling those wishing to be apart of the study may share similar characteristics such as outgoing qualities, implying there could be a sample bias and reduce the validity of the results. Therefore, limiting the amount we generalise the results due to a lack of representative.

Question 9

Sampling

Evaluation- Volunteer A03

Answer 9

Strength-
This may be considered the most ethical sampling method, the participants volunteer to be apart of the study, therefore providing consent for their involvement. This improves the ethics of the study as the participants were willing to take part not chosen and potentially coerced into it.

Weakness-
However, this method risks the influence of participant variables of the results. As all the participants volunteered they may be more motivated and helpful and so not reflective of the entire target population. This would make it harder to generalise the results as they may not be representative