Question

identify the sampling techniques used, and discuss potential sources of bias (if any). explain. after a wildfire, a disaster area is divided into 250 equal grids. forty of the grids are selected, and every occupied household in the grid is interviewed to help focus relief efforts on what residents require the most. what type of sampling is used? a. stratified sampling is used, since the disaster area is divided into grids, and a random sample is taken from each grid b. cluster sampling is used, since the disaster area is divided into grids, and some of those grids are selected and everyone in those grids is interviewed c. stratified sampling is used, since the disaster area is divided into grids, and some of those grids are selected and everyone in those grids is interviewed d. cluster sampling is used, since the disaster area is divided into grids, and a random sample is taken from each grid what potential sources of bias are present, if any? select all that apply. a. certain grids may have been much more severely damaged than others. severely damaged grids may have fewer occupied households. b. certain grids may have been much more severely damaged than others. the grids that are selected may not be representative in terms of damage. c. the sample only consists of grids that are easy to get. these grids may not be representative of the population. d. there are no potential sources of bias.

Explanation:

Cluster sampling divides the population into groups (clusters), selects some clusters, and includes all elements within the selected clusters. Here, the disaster - area is divided into grids (clusters), some grids are selected, and all occupied households in those grids are interviewed. For bias, grids may have different levels of damage, and the selected grids may not represent the overall situation well. Also, if the selection is based on ease of access, it may not be representative.

Answer:

What type of sampling is used?
B. Cluster sampling is used, since the disaster area is divided into grids, and some of those grids are selected and everyone in those grids is interviewed

What potential sources of bias are present, if any? Select all that apply
A. Certain grids may have been much more severely damaged than others. Severely damaged grids may have fewer occupied households.
B. Certain grids may have been much more severely damaged than others. The grids that are selected may not be representative in terms of damage.
C. The sample only consists of grids that are easy to get. These grids may not be representative of the population.