# p value interpretation in Mann-Kendall test

#### Fred_a

##### New Member
Hi,
I am performing a Mann-Kendall test on a set of a data. and I got a p value of 0.15 so it means the null hypothesis of NO TREND is not rejected. Does it mean that it it accepted and there is no trend in my data or it should be 0.95 to say that there is no trend in my data? how this p value can be interpreted?
Thank you

#### hlsmith

##### Less is more. Stay pure. Stay poor.
What program? Probably does not matter. Your first description seems correct. If your level of significance is 0.05 then a p-value > then 0.05 should be failure to reject the null hypothesis (no trend). Not familiar with this exact trend test, but guessing you can also generate a value for the trend along with 95% confidence interval to better interprete these data and perhap also plot them.

#### Fred_a

##### New Member
So the value more than 0.05 is the prove that the alternative hypothesis test (there is a trend) is rejected?

#### hlsmith

##### Less is more. Stay pure. Stay poor.
This is pretty standard formatting for p-values, but not knowing this test or which program used - it is just a well-formed guess. You should be able to look in a user manual or online documentation for the program you are using and its interpretation of the test.

#### Dason

##### Ambassador to the humans
So the value more than 0.05 is the prove that the alternative hypothesis test (there is a trend) is rejected?
Not quite. A p-value less than .05 allows you to reject the null hypothesis. That doesn't mean that a p-value above .05 rejects the alternative hypothesis - just that you can't reject the null hypothesis.

For example if I flip a coin once and it comes up heads I don't have enough evidence to reject the idea that the coin is fair. But that doesn't mean that I'm going to say that the coin definitely isn't biased because of the outcome of a single coin flip.