Two Stage Sampling and Their
Applications in Fisheries
Submitted by:
Semina Yasmin
M.F.Sc 1st Year
Course: Applied Fisheries Statistics (FST 513)
Abstract
Two-stage sampling is a widely-used technique in statistical surveys where data collection
occurs in two phases: selection of primary units followed by selection of secondary units
within them. This paper explores the conceptual framework of two-stage sampling, its
mathematical foundation, and specific applications in the field of fisheries science. Case
studies and practical advantages are discussed to highlight its effectiveness in fisheries
surveys.
1. Introduction
In statistics, sampling is an essential technique for gathering information about a population
without examining every element. Two-stage sampling is a form of multi-phase sampling
that involves selecting primary sampling units (PSUs) in the first stage and secondary
sampling units (SSUs) from each selected PSU in the second stage. This design improves
efficiency, especially in large-scale field surveys such as those conducted in fisheries.
2. Understanding Two Stage Sampling
In two-stage sampling:
- The first stage involves selecting clusters or groups, known as primary sampling units
(PSUs).
- The second stage involves selecting individual elements (secondary units) from within the
selected PSUs.
Let:
- Mi: Number of secondary units in the i-th cluster
- N: Total number of primary units in the population
- n: Number of primary units selected
- m: Number of secondary units selected within each chosen primary unit
- NM: Total number of elements in the population
Applications in Fisheries
Submitted by:
Semina Yasmin
M.F.Sc 1st Year
Course: Applied Fisheries Statistics (FST 513)
Abstract
Two-stage sampling is a widely-used technique in statistical surveys where data collection
occurs in two phases: selection of primary units followed by selection of secondary units
within them. This paper explores the conceptual framework of two-stage sampling, its
mathematical foundation, and specific applications in the field of fisheries science. Case
studies and practical advantages are discussed to highlight its effectiveness in fisheries
surveys.
1. Introduction
In statistics, sampling is an essential technique for gathering information about a population
without examining every element. Two-stage sampling is a form of multi-phase sampling
that involves selecting primary sampling units (PSUs) in the first stage and secondary
sampling units (SSUs) from each selected PSU in the second stage. This design improves
efficiency, especially in large-scale field surveys such as those conducted in fisheries.
2. Understanding Two Stage Sampling
In two-stage sampling:
- The first stage involves selecting clusters or groups, known as primary sampling units
(PSUs).
- The second stage involves selecting individual elements (secondary units) from within the
selected PSUs.
Let:
- Mi: Number of secondary units in the i-th cluster
- N: Total number of primary units in the population
- n: Number of primary units selected
- m: Number of secondary units selected within each chosen primary unit
- NM: Total number of elements in the population
