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What do you understand by p-value and what is use of it in ML?
P-value helps us determine how likely it is to get a particular result when the null hypothesis is assumed to be true. It is the probability of getting a sample like ours or more extreme than ours if the null hypothesis is correct.
How is P value calculated?
P-values are calculated from the deviation between the observed value and a chosen reference value, given the probability distribution of the statistic, with a greater difference between the two values corresponding to a lower p-value.
What is P value with example?
The p value is the evidence against a null hypothesis. The smaller the p-value, the stronger the evidence that you should reject the null hypothesis. P values are expressed as decimals although it may be easier to understand what they are if you convert them to a percentage. For example, a p value of 0.0254 is 2.54%.
What is the true p value of a t-test?
The true p-value is 0.15264, which is pretty close to our estimated p-value of 0.15. We saw in this post that it’s possible to estimate the p-value of a t-test by hand using the t-Distribution table.
What is the p value for the log rank test?
This gives a P value of 0.032, which indicates a significant difference between the population survival curves. An assumption for the log rank test is that of proportional hazards. This is discussed below. Small departures from this assumption, however, do not invalidate the test.
Do you have to use a calculator to calculate a p value?
In most cases, especially in rigorous statistical studies and experiments, you will want to use a calculator to find the exact p-value from a t-test so that you can be as accurate as possible, but it’s good to know that you can still estimate the p-value from a t-test by hand if you absolutely need to.
Which is the function of the survival function?
The survival function S(t) is defined as the probability of surviving at least to time t. The hazard function h(t) is the conditional probability of dying at time t having survived to that time. The graph of S(t) against t is called the survival curve.