2020-10-21

## What does a p-value of 0 indicate?

P value 0.000 means the null hypothesis is true. Anyway, if your software displays a p values of 0, it means the null hypothesis is rejected and your test is statistically significant (for example the differences between your groups are significant).

Can p-value ever be 0?

Note: Do not use 0 before the decimal point for the statistical value p as it cannot equal 1, in other words, write p = . 001 instead of p = 0.001.

### What does it mean if p-value is 0 in Anova?

It means ‘this evidence is literally impossible under the null hypothesis’. Example: If your null is “unicorns don’t exist”, and you observe one, you have p-value = 0.

How do you reject the null hypothesis with p-value?

If the p-value is less than 0.05, we reject the null hypothesis that there’s no difference between the means and conclude that a significant difference does exist. If the p-value is larger than 0.05, we cannot conclude that a significant difference exists. That’s pretty straightforward, right? Below 0.05, significant.

#### What does P .05 mean in statistics?

P > 0.05 is the probability that the null hypothesis is true. A statistically significant test result (P ≤ 0.05) means that the test hypothesis is false or should be rejected. A P value greater than 0.05 means that no effect was observed.

When is the p-value of a test really 1?

In some cases the p-value is not truly 1 but this is just an artifact of the statistical software (for example, when SPSS does Bonferroni correction, it sometimes reports p-values of 1, but this is not accurate). The only time a p-value is really 1 is in the situation Jochen described, i.e., when the test statistic is 0.

## How is the p value related to the rejection of h 0?

The p-value is a measure of the strength of the evidence in your data against H 0. Usually, the smaller the p-value, the stronger the sample evidence is for rejecting H 0. More specifically, the p-value is the smallest value of α that results in the rejection of H 0. For any value of α > p-value, you fail to reject H 0,…

Can a p-value be 1.0 in SPS?

The p-value can be exactly 1 in sps, if you use bonferroni correction. To avoid alpha-error cummulation when doing multiple pairwise comparisons sps multiplies the p-values by the number of comparisons. For example: If you compare 10 pairs every p-value >= 0,100 will be corrected to 1.

### Can a p-value be 1.0 in Fisher exact test?

No..P-value can never be one, if real data are compared. I met it in Fisher Exact test (2×2 table) when one group contains 0 and 14 and the other group contain 4 and 78. However, when the second group contains 9 and 73, the p-value was 0.34.