What does p-value say about null?
What does p-value say about null?
A p-value higher than 0.05 (> 0.05) is not statistically significant and indicates strong evidence for the null hypothesis. This means we retain the null hypothesis and reject the alternative hypothesis. You should note that you cannot accept the null hypothesis, we can only reject the null or fail to reject it.
How are p values and T values related?
The larger the absolute value of the t-value, the smaller the p-value, and the greater the evidence against the null hypothesis.
What does t test p-value mean?
In statistics, the p-value is the probability of obtaining results at least as extreme as the observed results of a statistical hypothesis test, assuming that the null hypothesis is correct. A smaller p-value means that there is stronger evidence in favor of the alternative hypothesis.
What is the null hypothesis for t test?
The default null hypothesis for a 2-sample t-test is that the two groups are equal. You can see in the equation that when the two groups are equal, the difference (and the entire ratio) also equals zero.
Is P 0.01 statistically significant?
Conventionally the 5% (less than 1 in 20 chance of being wrong), 1% and 0.1% (P < 0.05, 0.01 and 0.001) levels have been used. Most authors refer to statistically significant as P < 0.05 and statistically highly significant as P < 0.001 (less than one in a thousand chance of being wrong).
How do you reject or accept null hypothesis in t test?
If the absolute value of the t-value is greater than the critical value, you reject the null hypothesis. If the absolute value of the t-value is less than the critical value, you fail to reject the null hypothesis.
What should p value be for null hypothesis?
For a true null hypothesis, p can take on any value between 0 and 1 with equal likeliness. For a true alternative hypothesis, p-values likely fall closer to 0.
How to find the p value given a t value?
The right sided p p value corresponding to the negative t t value you found is between these two values p p value is the probability of finding the observed t t value or a smaller value, given that the null hypothesis is true. Find the upper tail probabilities corresponding to these two t t values.
What does it mean when p value is 0.05?
The p -value is a proportion: if your p -value is 0.05, that means that 5% of the time you would see a test statistic at least as extreme as the one you found if the null hypothesis was true.
When does the p value of a statistic get smaller?
The p-value gets smaller as the test statistic calculated from your data gets further away from the range of test statistics predicted by the null hypothesis. The p-value is a proportion: if your p-value is 0.05, that means that 5% of the time you would see a test statistic at least as extreme as the one you found if the null hypothesis was true.