Two-Sample Poisson Rate
Power and Sample Size
Power Analysis - Comparison Rates
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Two-Sample Poisson RatePower and Sample Size |
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The comparison rate is the rate you want to compare to the baseline rate. It is important to consider how small a difference between rates you are interested in being able to detect. Of course, you never actually know the values of the population rate when you conduct an experiment. Nonetheless, it is important to consider how small a difference you are interested in being able to detect.
If you provide the size of your sample and the power that you would like your test to have, Minitab will calculate the comparison rate that you will be able to detect with the indicated power.
Example Output |
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Test for 2-Sample Poisson Rate
Testing comparison rate = baseline rate (versus ≠) Calculating power for baseline rate = 250 α = 0.05 “Lengths” of observation for sample 1, sample 2 = 1, 1
Sample Comparison Size Power Rate 40 0.8 260.004 40 0.8 240.193 40 0.9 261.593 40 0.9 238.670
The sample size is for each group. |
Interpretation |
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For the post office data, the analyst wants to know what comparison rates can be detected when data is collected over 40 days and power is 0.8 or 0.9. The results indicate that the test can detect comparison rates of 260.004 and 240.193 when power is 0.8. The test can detect comparison rates of 261.593 and 238.670 when power is 0.9.
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