Introduction to Statistics Through Resampling Methods and R by Good Phillip I

Author:Good, Phillip I.
Language: eng
Format: epub
Publisher: Wiley
Published: 2012-12-13T16:00:00+00:00

Exercise 6.5: List all possible sources of variation for your hypothetical experiment and describe how you will cope with each one.

6.2.4 Matched Pairs

One of the best ways to eliminate a source of variation and the errors in interpretation associated with it is through the use of matched pairs. Each subject in one group is matched as closely as possible by a subject in the treatment group. If a 45-year-old black male hypertensive is given a blood-pressure lowering pill, then we give a second similarly built 45-year-old black male hypertensive a placebo.

Consider the case of a fast-food chain that is interested in assessing the effect of the introduction of a new sandwich on over-all sales. To do this experiment, they designate a set of outlets in different areas—two in the inner city, two in the suburbs, two in small towns, and two located along major highways. A further matching criterion is that the overall sales for the members of each pair prior to the start of the experiment were approximately the same for the months of January through March. During the month of April, the new sandwich is put on sale at one of each pair of outlets. At the end of the month, the results are recorded for each matched pair of outlets (Table 6.1).

Table 6.1 Sales (in $) of New Sandwich during April

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.