Certified Forester Practice Exam

Which type of sampling increases the estimated volume of timber by using subpopulations?

1. Stratified random sampling

2. Systematic sampling

3. Binary search sampling

4. Random sampling

The correct answer is: Stratified random sampling

Stratified random sampling is a technique used in forestry and other fields where populations are divided into distinct subpopulations, known as strata, based on specific characteristics such as age, species, or volume. By ensuring that each stratum is adequately represented in the sample, this method increases the likelihood of obtaining an accurate estimate of the total volume of timber. This approach is particularly beneficial in forestry because it accounts for variations within the forest that may affect timber volume, leading to more precise and reliable estimates compared to other sampling methods. The unique subpopulations can have different growth rates, densities, or management histories, and stratified sampling captures these nuances, enhancing the overall volume estimation. In contrast, systematic sampling, binary search sampling, and random sampling do not focus on segmenting the population into subgroups in the same way. Systematic sampling may introduce bias if the patterns in the data align with the systematic approach, while random sampling lacks structure and may not adequately represent all groups in a heterogeneous population. Binary search sampling, while useful in certain contexts, doesn’t apply directly to the estimation of timber volume through stratified methods.