sampling techniques

Question 1

sampling techniques

Answer 1

When conducting a piece of research, your sample refers to the groups of people that form part of the research process.
Selected via a process of sampling.
• Opportunity
• Volunteer
• Random
• Systematic
• Stratified

Question 2

population vs sample

Answer 2

When conducting a piece of research, a researcher is generally interested in a large group of people.
This is known as the target population.
• The population is then reduced down to a smaller group, known as a sample
• This sample should be as representative of the target population as possible.
→ Generalisability of results.

Question 3

opportunity sampling

Answer 3

Researchers simply decided to select anyone who happens to be willing and available. The researchers simply takes the opportunity to ask whoever is around at the time of their study

Strengths:
• Very convenient
• Very economical
-both of these as no complex selection process

Weaknesses:
• Unrepresentative Sample-people walking past at that time of day wouldn’t represent population-eg volunteer sampled at school
• Research Bias

Question 4

volunteer sample

Answer 4

This sampling technique involves participants selecting themselves to be part of the sample.
Strengths:
• Minimal effort
• Not time consuming

Limitations:
• Volunteer Bias
• May all have similar characteristics which might not represent the population.-eg more motivated

Question 5

systematic sampling

Answer 5

This type of sample is when every nth member of the target population is selected.
• Members of the target population are sorted into a list, before being selected.(organised in a particular way eg alphabetically)

This type of sample is when every nth member of the target population is selected.
• Members of the target population are sorted into a list, before being selected.

Strengths:
• Free from researcher bias, as the researcher has no control over who gets picked.

Limitations:
• Time consuming
• In the end participants may refuse to take part → results in volunteer sample.

Question 6

random sampling

Answer 6

This type of sampling is a sophisticated form of sampling in which all members of the target population have an equal chance of being selected.

eg arrange students in order alphabetically and assign number and then use random number generator

Strengths:
• Free from bias
• Representative
• EVs and CVs are evenly distributed → Increased internal validity.

Limitations:
• Difficult and time consuming
• A complete list of the target population may be hard to obtain
• Could still be unrepresentative

Question 7

stratified sampling

Answer 7

Population:
Patients in psychiatric hospital.
• 40% depression
• 40% Bi-Polar
• 15% personality
disorder
5% schizophrenia.

Sample:
20 Patients from the same hospital
8 with depression
• 8 with Bi-Polar
• 3 with personality disorder
• 1 with schizophrenia.

The composition of the sample reflects the proportions of people in certain subgroups (strata) within the target population or the wider population.

Strengths:
• Produces a representative - it accurately reflects the compositions of society.
• Sample is generalizable

Limitations:
• Stratifying cannot represent all of the ways in which people are different and so a complete representation of the target population is not possible.