Sampling Methods
Techniques used to select individuals or items from a population to create a sample.
Examples:
Random Sampling: Every member has an equal chance of selection.
Stratified Sampling: Population is divided into subgroups, and samples are taken from each.
Systematic Sampling: Selection at regular intervals (e.g., every 10th item).
Important Note: The choice of sampling method can influence the accuracy and bias of results.
Sample
A subset of the population selected for analysis.
Example: 100 students selected from a school of 1,000 students.
Important Note: The sample should represent the population well to ensure valid results.
Sampling Unit
An individual element or item from the population that can be chosen for the sample.
Example: Each student in a school survey.
Important Note: A sampling unit is the “building block” of a sample and should be clearly defined.
Sampling Frame
A list or database of all sampling units in the population, used as a source to select a sample.
Example: A list of all students in a school.
Important Note: A well-defined sampling frame is crucial for accuracy, as missing or duplicated entries can skew results.
Sample Size
The number of units included in a sample.
Example: In a survey, choosing 200 people as the sample size.
Important Note: A larger sample size generally provides more accurate results but may increase cost and complexity.