Sampling Methods

Random Sampling

Researchers randomly choose participants from a larger population

Characteristic of Random Sampling

• Each individual in the population has an equal chance of being selected

• Independent selectio

Strengths of Random Sampling

• Reduces researcher bias

• More generalizable to the population / higher population validity

• Better for statistical tests

Limitations of Random Sampling

• Not feasible for large populations

• Costly/time-consuming

Purposive Sampling

Participants are selected based on specific characteristics or criteria relevant to the study

Characteristics of Purposive Sampling

• Non-random selection

• Participants selected based on characteristics/criteria

• Usually used in qualitative research

• Small sample sizes

Strengths of Purposive Sampling

Allows for in-depth study of specific groups, enhances the relevance of data, and can provide richer qualitative insights.

Limitations of Purposive Sampling

• Low population validity/generalizability

• Potential for researcher bias

• Not suited for statistical analysis

Volunteer sampling

Participants self-select to be part of a study

Characteristics of Volunteer sampling

• Researcher usually uses some marketing to advertise the study

• Participants are the ones that approach the researcher

Strengths of Volunteer Sampling

• Efficient and cost-effective

• Potential for diverse participants

• Ethical

Limitations of Volunteer Sampling

• Potential for bias due to self-selection

• Participant Expectancy effect

• Limited generalizability / population validity

Convenience Sampling

Participants are selected based on their proximity/closeness to the researchers

Characteristics of Convenience Sampling

• Non-random

• Participants were chosen based on accessibility

Strengths of Convenience Sampling

• More efficient

• Cost-effective

Limitations of Convenience Sampling

• Low population validity / generalizability

• Potential Sampling bias

• Difficult to replicate by others

Snowball Sampling

Study participants recruit future participants from their social networks

Characteristics of Snowball Sampling

• Typically used to study a marginalized/hard-to-reach population

• Non-random

• sample size grows exponentially (snowballing)

Strengths of Snowball Sampling

• Can access hard-to-reach populations

• Cost-effective and convenient

• Good for qualitative research

Limitations of Snowball Sampling

• Low population validity

• Potential for participant bias

• Ethical considerations