SAMPLE-AND-SAMPLING-TECHNIQUE

Introduction to Sampling

  • Definition: A population is a group of individuals or objects sharing a common trait or characteristic.

  • Purpose of Sampling: Researchers collect data from a population to study and make conclusions about the target population.

Types of Population Samples

Sample Population

  • Concept: The sample population is a subset of the population that is studied to represent the entire population.

Sampling Techniques

Types of Sampling Procedures

  • Deliberate Sampling

  • Simple Random Sampling

  • Systematic Sampling

  • Stratified Random Sampling

  • Cluster Sampling

Non-Probability Sampling

  • Also referred to as Deliberate/Purposive Sampling.

  • Characteristics: Samples are predetermined by researchers based on convenience, making it easier to gather data.

  • Limitations: This method is highly susceptible to sampling biases.

Convenience Sampling

  • Definition: A sample that includes individuals who are easy to reach, such as asking people if they have pets at home.

Simple Random Sampling (SRS)

  • Definition: An unbiased sampling method where every individual in the population has an equal chance of being selected.

  • Method: Often involves a lottery method.

Systematic Sampling

  • Concept: Involves selecting samples based on a fixed, periodic interval.

  • Procedure:

    1. Determine Population Size (N) and desired number of samples (n).

    2. Calculate Interval Size (k): Divide N by n.

    3. Select a Random Start to pick the first sample.

    4. Select Subsequent Samples: Choose every kth member of the population.

Stratified Random Sampling

  • Purpose: Used to create representative samples from heterogeneous populations by grouping into strata based on similar characteristics.

  • Types: Can be proportionate (sizes of groups reflected in samples) or disproportionate (different sample sizes taken from various groups).

Cluster Sampling

  • Definition: Subjects are grouped into smaller subpopulations or clusters based on specific factors or existing groupings.

  • Application: Allows for easier management of the subjects being sampled.