Certified Forester Practice Exam

What is considered a disadvantage of systematic sampling?

1. It may not accurately estimate the mean forest conditions

2. It is too expensive to implement

3. It takes too long to sample

4. It can cause data redundancy

The correct answer is: It may not accurately estimate the mean forest conditions

Systematic sampling involves selecting samples at regular intervals across a study area. One significant disadvantage of this method is that it may not accurately estimate the mean forest conditions, particularly if there are patterns or trends present in the landscape that correspond with the sampling interval. For example, if the trees or features being measured follow a distinct periodic pattern, using fixed intervals might lead to overrepresenting or underrepresenting certain areas, ultimately skewing the results. This lack of randomization can make it difficult to capture the true variability and average conditions of the forest ecosystem, thus potentially compromising the overall accuracy of the mean estimates. The other options focus on aspects like cost, time, and redundancy, which are not primary concerns with systematic sampling. Although there could be scenarios where implementation might require considerable resources or time, these factors are not inherent disadvantages of the sampling technique itself but rather can depend on specific project designs and resource allocations. Additionally, systematic sampling does not intrinsically cause data redundancy; this issue arises from other sampling methods or poor study design.