Sampling Techniques

Quantitative Continuous

A type of data that can take any value within a given range, such as height, weight, and temperature.

Quantitative Discrete

A type of data that can only take specific, distinct values, like the number of students in a class or cars in a parking lot.

Sampling Techniques

Methods used to select a subset of individuals from a population to estimate characteristics of the whole population.

Random Sampling

A technique where every member of the population has an equal chance of being selected, reducing bias.

Stratified Sampling

A method where the population is divided into subgroups (strata) and random samples are taken from each stratum.

Systematic Sampling

A sampling method where members are selected at regular intervals from a randomly ordered list.

Cluster Sampling

A technique that divides the population into clusters and randomly selects entire clusters.

Convenience Sampling

A method where samples are taken from a group that is easily accessible, potentially introducing bias.

Probability Sampling

A technique where each member of the population has a known, non-zero chance of being selected.

Non-Probability Sampling

A technique where not all members have a chance of being selected, which can lead to biased results.

Simple Random Sampling

A type of probability sampling where each member has an equal chance of being selected, often using random number generators.

Purposive Sampling

Also known as judgmental sampling, where researchers select participants based on specific characteristics or criteria.

Quota Sampling

A method that divides the population into subgroups and sets quotas to ensure certain characteristics are represented in the sample.

snowball sampling technique

Snowball Sampling Technique

Definition: Snowball sampling is a non-probability sampling technique used in qualitative research. It is particularly useful for populations that are hard to access.

Process:

1. Initial Participants: Start with a small group of initial subjects.

2. Referrals: These subjects then refer other participants.

3. Expansion: This process continues, creating a "snowball" effect as more participants are recruited through existing ones.

Advantages:

• Effective for hidden populations (e.g., drug users, homeless individuals).

• Cost-effective and time-efficient.

Disadvantages:

Snowball Sampling Technique

Definition: Snowball sampling is a non-probability technique in qualitative research, ideal for hard-to-access populations.

Process:

1. Initial Participants: Begin with a small group.

2. Referrals: Participants refer others.

3. Expansion: This continues, creating a "snowball" effect.

Advantages:

• Effective for hidden populations (e.g., drug users, homeless).

• Cost-effective and time-efficient.

Disadvantages:

• Potential bias; sample may not be representative.

• Limited generalizability of results.

• Potential for bias, as the sample may not be representative.

• Limited generalizability of results.