1

What I currently understand about the P-value is that, if the null hypothesis were true, the P-value is the probability of getting a value of the sample test statistic that is at least as extreme as the one found from my sample data.

What I don't understand is, if I have a two-tailed test and I am assuming my null hypothesis were true (for example hypothesizing that my mean is equal to 2) and my P-value (probability of obtaining extreme values further from 2) is very low, wouldn't that favour my null hypothesis because the probability of obtaining extreme values that are further from the hypothesized mean of 2 is lower?

Why is it that the lower the P-value, the stronger evidence I have to reject my null hypothesis?

Please let me know where I have gone wrong in my understanding.

melm
  • 11
  • 1
  • Are you going to find your null hypothesis more plausible when your sample mean is *close* to the hypothesized mean, or when it's *very far* from the hypothesized mean? – Glen_b Oct 22 '17 at 03:54
  • In your second para, what do you understand by my mean is equal to 2 ? Is it t- statistic ? How do you compute it ? –  Oct 22 '17 at 11:14
  • After reading https://stats.stackexchange.com/questions/31, are there any parts of this question that remain unanswered? – whuber Oct 22 '17 at 16:34
  • @Glen_b I would have that thought that my null hypothesis is plausible when my sample mean is close to the hypothesized mean. This is why I thought that having a low probability of my sample mean being very far from from the null hypothesis would mean that my null hypothesis is more plausible. Where have I gone wrong? – melm Oct 24 '17 at 02:20
  • @whuber I read through the post, and again, I do understand the concept of the P-value being the probability of obtaining a value at least as extreme as the one found from my sample data, which I think is a lot of what the post explained. My main concern, is once I obtain my P-value, why is it that the lower the P-value the more likely I am to reject my null hypothesis. I conceptually do not understand this. – melm Oct 24 '17 at 02:25

0 Answers0