methods of sampling

population

A complete or entire group of people, items, or data that share at least one characteristic relevant to a research study the researcher wants to study.

target population

The entire group that the researcher wants to study and make conclusions about.

-It is the ideal group.

-Usually bigger and sometimes impossible to reach completely.

accessible formulation (sampling frame)

The portion of the target population that the researcher can actually reach, contact, or study.

•  Smaller than the target population.

• The sample is selected from this group.

• It depends on location, time, resources, or permissions.

sample

-A smaller group selected from the population.

-A subset of the accessible population that eventually participates in the Action Research.

sampling

is a process of selecting a small group of individuals, items, or cases from a larger population so that the researcher can study the smaller group and make conclusions about the whole population.

probability sampling

-Sampling technique where every member of the population has a known and equal chance of being selected.

-This method is considered the most scientific and reliable because it reduces bias and allows generalization of results.

simple random sampling

(PS) Process of selecting research participants from the accessible population wherein each member of the subset has an equal chance of being chosen.

systematic sampling

(PS)• Individuals are selected at regular intervals from the sampling frame.

• The intervals are chosen to ensure an adequate sample size.

• If you need a sample size n from a population size x, you should select x/n individual for the sample.

stratified sampling

(PS) •The population is divided into subgroups (strata) based on characteristics

•Then samples are taken from each subgroup randomly.

cluster sampling

(PS)• subgroups of the population are used as the sampling unit, rather than individuals.

•The population is divided into subgroups, known as clusters, which are randomly selected to be included in the study.

multi-stage sampling

(PS) Sampling is done in several stages using combinations of techniques (cluster, random, systematic, etc.).

non-probability sampling

-Is defined as a sampling technique in which the researcher selects samples based on the subjective judgment of the researcher rather than random selection.

convenience sampling

A non-probability sampling technique where the researcher selects participants who are easily available, accessible, and willing to participate.

quota sampling

- A non-probability sampling method where the researcher selects participants based on pre-set quotas that represent certain characteristics of a population (e.g., age, gender, grade level).
- Participants are chosen until each quota is filled.

purposive sampling/selective sampling

A non-probability sampling technique where the researcher intentionally selects participants based on specific criteria, qualifications, or expertise needed for the study.

snowball sampling

- A non-probability sampling method used when the population is hard to locate.
- Researchers ask initial participants to refer or recruit other people who also fit the study criteria — like a snowball growing as it rolls.