Question

Which one of the following is different from other sampling methods?

• A. Multistage sampling
• B. Multiphase sampling
• C. Stratified sampling
• D. Systematic sampling

Hint:

To distinguish these concepts, remember that *multistage* sampling uses different, smaller units at each successive stage, whereas *multiphase* sampling uses the same sample units but with different levels of detail at each phase.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Forest inventory and ecological studies rely on various sampling techniques to estimate stand parameters like volume, basal area, and species richness.
These sampling methods are categorized based on their structural design, selection probability, and the stages of data collection.

Step 2: Detailed Explation:
Let us alyze and contrast the different sampling methods:
- Stratified Sampling, Systematic Sampling, and Multistage Sampling: These are structural sampling designs where the fil selection of sampling units is determined in a single continuous process.
- In stratified sampling, the population is divided into homogeneous strata, and samples are drawn from each stratum.
- In systematic sampling, units are selected at regular, predetermined intervals.
- In multistage sampling, the population is divided into primary, secondary, and tertiary stages of nested units to select the fil sample.
- Multiphase Sampling: This method is fundamentally different because it involves collecting data from the same sampling units at different phases or levels of detail.
For example, in two-phase sampling, a large sample is selected in the first phase to gather easy-to-measure auxiliary data (such as crown cover from aerial photographs), and then a smaller subsample is selected in the second phase to measure the primary variable of interest (such as ground-measured wood volume).
Because multiphase sampling relies on subset relationships of measurements rather than nested structural subdivisions of the population, it stands distinct from the other listed methods.

Step 3: Fil Answer:
Multiphase sampling is distinct from stratified, systematic, and multistage sampling because it varies the intensity of data collected on sub-samples of the same units.
Hence, the correct option is (B).