How much variance in my p-value

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    P-value Variance
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SUMMARY

The discussion centers on the variability of p-values obtained from chi-squared goodness-of-fit tests applied to datasets following a Poisson distribution. The user reports p-values of 0.5, 0.7, 0.8, 0.2, and 0.3 across five datasets, questioning the normality of this variance. It is established that while p-values can differ between datasets, a significant fluctuation in the reference p-value is atypical and warrants further investigation into the underlying data and methodology.

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  • Understanding of Poisson distribution
  • Familiarity with chi-squared goodness-of-fit tests
  • Knowledge of p-value interpretation
  • Experience with statistical analysis software (e.g., R, Python)
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  • Investigate the assumptions of the chi-squared goodness-of-fit test
  • Learn about Poisson distribution characteristics and applications
  • Explore methods to stabilize p-value calculations across datasets
  • Review statistical software packages for conducting chi-squared tests (e.g., R's chisq.test function)
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Statisticians, data analysts, researchers conducting hypothesis testing, and anyone involved in statistical modeling of count data.

Nyasha
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So l have a nuclear counting system which follows a poisson distribution. I have taken 5 data sets consisting of 30 counts each and l have used them in a chi squared gof test to see if they follow a poisson distribution. For each data set my p-value has been changing. Initially it was 0.5 then 0.7, 08, 02, 0.3 Is this normal or is it a cause of worry ?
 
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The p-value you get off the chi-square test will be different between datasets, that is normal. It is not normal for the reference p-value to change.
Consider: what does the p-value actually represent?
 

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