Practical Research - Sample Size Determination using Slovin’s Formula

Sample

individual that represent the entire population of a target
respondents of the study.

Population

group of individuals that the researcher is interested in
studying that usually has common or similar characteristics.

Sampling Frame

complete list of all cases in the population from which
the sample will be drawn.

Slovins Formula

statistical formula used to obtain an accurate sample size
(n) given the population (N) and margin of error (e). Margin of error (e) is the allowable error margin in research.

Probability Sampling

sampling technique in which samples are
obtained using some objective chance mechanism, thus involving randomization.

Simple Random Sampling

selection is the same for every member of the population.

Systematic Random Sampling

follows regular intervals from a list. It has a specific steps and procedures in doing the random selection of the samples.

Stratified Random Sampling

The population is divided into groups (strata) then simple random sampling is applied in selecting samples from each group.

Cluster Sampling

used when the target respondents in a research study is spread across a GEOGRAPHICAL LOCATION. In this method, the population is group into what we called CLUSTER. Simple random sampling is used in selecting the cluster.

Multi-Stage Sampling

procedure as in cluster sampling which moves through a series of stages.

Non-Probability Sampling Technique

gives equal chance of selection to all members of the
population, is a sampling technique that does not give
all the samples in the population equal chances of being selected.

Convenience Sampling

method of selecting samples that are
conveniently available to participate to the researchers’ study. This method is also called availability sampling.

Purposive Sampling

also called judgmental or subjective sampling. In
this method, the researcher chooses only those respondents that he thinks suitable to the study.

Quota Sampling

sampling technique wherein the researcher makes sure
of equal or proportionate representation of subjects depending on which trait is considered as basis of the quota. The bases of the quota are usually age, gender, education, race, religion and socioeconomic status.

Snowball Sampling

sampling technique wherein the researcher looks for a
respondent to participate in the study then ask that respondent to refer another respondent who can participate in the study. This is used when researcher finds it difficult to locate special numbers of a population.