Question

The DNR is planning a study to determine whether breakwaters help decrease erosion at a large lake. They divide the shoreline into 100-foot plots, installing some with breakwaters and some without. However, the east and west shorelines of this lake receive very different wave patterns due to the wind. The DNR suspects this will affect the responses to the breakwaters. Because of this, the DNR plans to treat each shoreline as a different group. This study is an example of__________.

(A) An uncontrolled experiment
(B) A blocked design experiment.
(C) A matched pairs experiment.
(D) A stratified random sample
(E) A randomized observational study

Answer 1

Option B: A blocked design experiment

Explanation:

A blocked design experiment takes into cognizance that there is one factor or variable that is of primary interest. However, there are also several other nuisance factors that may affect the measured result. The experimenter will have to look into which nuisance factors are important enough to keep track of or control, if possible, during the experiment which in this case is "However, the east and west shorelines of this lake receive very different wave patterns due to the wind". This can be controlled to reduce the contribution of experimental errors thus treating each shoreline as a different group.