Introduction to ClusterSampling
• Cluster Sampling is a probability sampling
method where the population is divided into
groups (clusters), and a random sample of
these clusters is selected for study.
– Each cluster should ideally represent the entire
population, making it easier and more cost-
effective to collect data.
3.
Definition
• Cluster samplinginvolves dividing a
population into clusters, then randomly
selecting some clusters, and collecting data
from all units within the chosen clusters.
4.
Steps in ClusterSampling
– 1. Define the population clearly.
– 2. Divide the population into clusters.
– 3. Select clusters randomly using probability
sampling.
– 4. Collect data from all or a sample of units within
selected clusters.
– 5. Analyze and interpret the results.
5.
Types of ClusterSampling
– Single-Stage Cluster Sampling – All elements from
selected clusters are studied.
– Two-Stage Cluster Sampling – Random samples
are drawn from within selected clusters.
– Multistage Cluster Sampling – Combines multiple
stages of sampling for large-scale studies.
6.
Example of ClusterSampling
• Suppose a researcher wants to survey
students in a country. Instead of selecting
individual students, schools (clusters) are
randomly chosen, and all students in those
schools are surveyed.
7.
Advantages of ClusterSampling
– Cost-effective for large and dispersed populations.
– Simplifies data collection and management.
– Suitable for geographically spread populations.
– Requires fewer resources compared to simple
random sampling.
8.
Disadvantages of ClusterSampling
– Less precise than simple random or stratified
sampling.
– High sampling error if clusters are not
homogeneous.
– Bias may occur if clusters differ significantly.
9.
Cluster Sampling vsStratified
Sampling
– In cluster sampling, clusters are randomly
selected; in stratified sampling, elements are
chosen from every stratum.
– Clusters are mini-populations; strata are
homogeneous subgroups.
– Cluster sampling reduces cost; stratified sampling
increases accuracy.
10.
Applications of ClusterSampling
– Used in large-scale government surveys like
census studies.
– Applied in education and health surveys.
– Common in marketing research to study consumer
behavior in different regions.
11.
Summary
• Cluster Samplingis a cost-efficient and
practical sampling method for large
populations, especially when elements are
naturally grouped. However, care must be
taken to ensure clusters are representative to
minimize bias.