In: Statistics and Probability
The managers of three different supermarkets in the US desire to test the effectiveness of a new store design on sales. The manager of supermarket A decides to let store directors choose on their own whether they judge appropriate to implement the new design. The manager of supermarket B randomly chooses stores to assign the new design. The manager of supermarket C randomly draws stores in each US State separately.
(a) State whether each of the three experimental designs is observational or experimental, providing an explanation.
(b) Which experimental design is implemented in each of the three studies?
(c) Which kind of bias will arise from design A? Why?
(d) Compare the quality of statistical results from Designs B and C. State which of the two prevails on your opinion and why.