Questions tagged [p-value]
In frequentist hypothesis testing, the $p$-value is the probability of a result as extreme (or more) than the observed result, under the assumption that the null hypothesis is true.
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Calculate p-value for identical groups
I am preparing a baseline characteristics table for two independent groups.
One of the numerical variables (x) has the exact same value for all participants in both groups:
Group 1 (n = 90): all ...
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Why does the p-value increase when I add more observations to my t-test?
I am comparing the means of two groups using an independent two-sample t-test in R. Initially, I had the following samples:
Group A: n = 15, mean = 52.3, sd = 4.8
Group B: n = 15, mean = 48.1, sd = 5....
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Why can I fit a horizontal line through the 95% confidence intervals region of my OLS model even though its overall p-value is close to 0.05?
Original question: ~~I don't know how to intrepet the result I got from my OLS analysis. The issue is that I can fit a horizontal line within the 95% CI even though the overall p-value for the model ...
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Guarantees of different experiments with the same p-value
Frequentists often explain that:
If we construct a 95% confidence interval for the mean of some unknown distribution using n random samples from a population, the ...
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How to deal with missing standard errors from primary studies in meta-analyses?
I'm conducting a meta-regression in the field of Economics where my primary studies are regression analyses. To ensure comparability between regression results, I'm only considering regressions that ...
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Why do tidycmprsk::crr() and survival::coxph() on survival::finegray() data give identical coefficients but different SEs, CIs and p-values?
I’m comparing the results of a Fine–Gray competing risks regression using tidycmprsk::crr() and a Cox model fitted to the Fine–Gray expanded data created with ...
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What qualifies to be a "family of statistical tests" for Bonferroni corrections?
I have looked at posts about multiple hypotheses, but not found what I'm looking for.
I have different sets of statistical analyses in my paper:
Comparisons of valid to excluded data (8 tests; just ...
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Does autocorrelated independent variable in a regression cause issues with t-stat estimate?
I saw the below question in an exam:
We have $X_t$ and $Y_t$ that are i.i.d. time series. Let $A_t = X_t + X_{t-1} + X_{t-2} + X_{t-3} + X_{t-4}$. We regress $Y_t \sim \alpha + \beta \cdot A_t$ and ...
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Analyzing test result using test statistic vs p-value?
I am trying to understand how/when to use a test-statistic and/or p-value to draw a conclusion on a test.
As far as I understand, when running a statistical test we must decide whether to use the test ...
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Multiple comparisons correction for MRI region-of-interest analysis
I am investigating associations between four predictors and grey matter volume (GMV) in 16 different regions of interest. To do that, I have performed 16 multiple linear regressions:
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Why don't people add "coverage" intervals on the p-values they report? (E.g. from bootstrapping the sampling distribution of p-values)
Let's say i want to test for the difference of mean values of two distinct groups having each N observations. The null hypothesis would be that there is no difference - this could for example be ...
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Reporting p-values as an inequality or an exact value? [duplicate]
Should p-values be reported as an inequality (e.g. p<0.05) rather than the actual value (e.g. p=0.04)? If it is a binary decision as to whether results are significant, wouldn't stating p<0.05 ...
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What information do p-values and confidence intervals provide?
I am in the field of medical research and had a few questions regarding statistics. Is it preferred for a study to state both p-values and confidence intervals together? What extra information do ...
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Trouble with the definition of p-value
I'm following a statistics course and our professor gave us a definition of p-value I'm having some trouble understanding. First, some preliminary notations I want to set:
$\Omega = A \cup A^\...
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Minimal conditions to define rejection regions in hypothesis testing
I have a conceptual question about hypothesis testing. I would like to know what are the minimal conditions that a statistic and its rejection regions must satisfy in order for a test of a null ...
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