All of the following holds true about cluster sampling, except:
**Core Concept**
Cluster sampling is a probability sampling technique used in epidemiology and medical research. It involves dividing the population into clusters or groups, and then randomly selecting a subset of these clusters to participate in the study.
**Why the Correct Answer is Right**
Cluster sampling is a type of sampling method where the population is divided into clusters, and a random sample of these clusters is selected. This approach is particularly useful when conducting surveys or studies in areas with limited resources or infrastructure. By selecting clusters, researchers can reduce the costs and logistical challenges associated with data collection. Additionally, cluster sampling can provide more accurate estimates of the population's characteristics, as it takes into account the geographic and demographic characteristics of the clusters.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because cluster sampling does involve selecting a random sample of clusters, which is a key characteristic of this sampling method.
**Option B:** This option is incorrect because cluster sampling is often used in combination with other sampling methods, such as stratified sampling, to increase the accuracy of estimates.
**Option D:** This option is incorrect because cluster sampling can be used to estimate the population's characteristics with a high degree of accuracy, particularly when the clusters are well-defined and representative of the population.
**Clinical Pearl / High-Yield Fact**
One key advantage of cluster sampling is that it can reduce the costs and logistical challenges associated with data collection, making it a more feasible option for researchers in areas with limited resources.
**Correct Answer: A. This option is incorrect because cluster sampling does involve selecting a random sample of clusters, which is a key characteristic of this sampling method.**