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The Conclusion

The purpose of the Conclusion stage is to report the results of the study in the language of the Problem. Concise numerical summaries and presentation graphics should be used to clarify the discussion. Statistical jargon should be avoided. As well, the Conclusion provides an opportunity to discuss the strengths and weaknesses of the Plan, Data and Analysis especially in regards to possible errors that may have arisen. The error classification that we have developed provides a structure for this discussion.

In Michelson's study, he concludes by reporting the speed of light (km/s) in vacuo as $299944 ~\pm 51$. He then discusses possible ``Objections'' including among others not mentioned above, uncertainty of the laws of reflection and refraction in media in rapid rotation, retardation caused by reflection, imperfections in the lens, periodic variation in friction at the pivots of the rotating mirror and change of speed of rotation. In each case, he refers back to the Plan and the model assessment to demonstrate that the objection would have little effect on the estimate of the speed of light.

In our language, we would start with the reported speed of light based on the confidence interval. Other than the discussion given by Michelson, we would add the possible error due to the difference between the target and study population.

We can find no reason in the paper as to why there is such a relatively large error in Michelson's final reported speed. Note that the defined true value is well outside both the confidence interval and Michelson's interval of plausible values.


next up previous
Next: Discussion Up: Statistical Method and Michelson's Previous: The Analysis

2000-05-24