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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Do p-values assume an unlikely event has already happened?

According to this thread What is the meaning of p values and t values in statistical tests? a p-value essentially lets me compare the probability of tail-end (unlikely) events occurring and judging ...
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10 views

Mixed-effect models for repeated measures - problems with the “Significance level”

I am trying to fit a linear mixed-effect model to my dataset to see the relationship between a self-reported questionnaire and some physiological data. I've created a first model including all the ...
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10 views

Fixing degenerate p-values from doing logistic regression with R glm.fit [on hold]

I'm using glm.fit to look at DNA methylation data- each site in the data set is covered by reads labeled either C or T, where Cs indicate methylation. Thus the reads are being generated by a binomial ...
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14 views

Why does a low p-value mean there is sufficient evidence to reject the null hypothesis? [duplicate]

As I understand it, a p-value is the prob of getting something as far or farther out in the tails of a normal distribution than the observed t value. source In other words, $$\Bbb P(\text{value ...
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19 views

Combine multiple independent permutation tests

I want to find out whether a neural measure measured at 12 time-points is correlated with a behavioral measure measured on the same time-points. I have data from 20 subjects. I'm hoping to perform a ...
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8 views

Can I extrapolate a mean difference from the t-statistic?

I have the t-statistic, df, p and cohen's d for the one-tailed independent samples t-tests on the difference between a parameter for cases and controls. I would like to obtain a mean difference and ...
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10 views

Can I obtain a mean difference from fold change data, number of participants and p values?

I have gene expression in fold change for cases vs controls. I have the number of participants for the cases and controls. I have the p value obtained for the case gene-expression by univariate ...
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3 views

Interpreting pvalue by confronting the observed difference with the expected one (minimum clinically important difference (MCID))

Let's say I study the association between a dichotomic variable (a treatment) and a quantitative one, which is my primary endpoint Let's say I know the minimum clinically important difference ...
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14 views

Statistic Questio- P Value Method? [on hold]

I'm having trouble determining what the P-value method is: Two types of flares are tested and their burning times are recorded. The summary statistics are given below. Use a 0.05 significance level ...
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17 views

Calculating p-value based on Chi-Square vs Z-Test incl Standard Error

I have been testing the significance levels for my various a/b tests. Degree of freedom is 1 so there's not a lot of complications here. So far I've been calculating my results using Chi-Squared ...
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1answer
25 views

Does the p value for logistic regression depends on odds ratio or logit?

The p value in a logistic regression is given for the B estimates. But what if I'm reporting odds ratio instead of logit. Do the same p values apply?
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Robustness of correlation test to non-normality

I'm trying to reconcile two seemingly opposite statements about robustness to non-normality of the Pearson's correlation test statistic (where the null means "no correlation"). This CV answer says: ...
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16 views

Best approach for calculating confidence score (p-value) - for Bayes models

This is a generic question on the best approach for giving a p-value to a "most likely" solution given by a graphical Bayes model. I am building a graphical model in Stan, for finding the most likely ...
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13 views

Combine Results of One- and Two-Tail Tests? [closed]

Can you combine the results of a One- and Two-Tail tests for the SAME sample to draw an inference about population parameter? One-Tail Test: Ho: p ≥ 90% Ha: p < 90% P-value: 0.514 > α .05 ...
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27 views

How to say “the statistical significance of our result is stronger”?

I'm doing a Bonferroni correction, after which our result is still significant at the 10% level. Since my multiple outcomes are highly correlated, for which the Bonferroni is too conservative, I want ...
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1answer
41 views

Contradictory results of the ADF test in R [closed]

I used the urca pacakge in R to run the ADF test and got the following: It seems to me the results are quite contradictory: Using the statistic, we fail to reject the null hypothesis; However, ...
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11 views

Interpreting Tukey HSD p-value After ANOVA + FDR correction

I'm currently analyzing a dataset where I have gene expression pathway activation scores across three groups: two different treatments and one control (so, basically a matrix of the form pathways x ...
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1answer
46 views

P-value & Confidence Interval…I choose you CI!

I'm struggling with an interpretation of p-value and confidence interval. They are both in agreement, but yet, can't be used together to make one statement about population proportion. So...am I ...
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4 views

Simulating thousands of regressions and obtaining p-values [migrated]

I'm looking to do some basic simulation in R to examine the nature of p-values. My goal is to see whether large sample sizes trend towards small p-values. My thought is to generate random vectors of ...
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6 views

Unsure of how to test a mixture model coefficient and standard error.

This is my first question on Stack Exchange so please excuse any faux pas! I've been working with a mixture model from the paper "Efficient estimation for an accelerated failure time model with a ...
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20 views

How to adjust p-value to reject null hypothesis from sample size in Mann Whitney U test?

I am trying to test if the shape and median of two samples are significantly different using Mann Whitney U test (or wilcox.test in R). The two samples (A and B), ...
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26 views

Machine Learning Algorithms For Poor Quality Statistics

I'm looking for references on any work done in the area of machine learning for automated detection of poor quality papers that use statistics (for example p-value hacking, misunderstanding confidence ...
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1answer
64 views

Conclusion from Hypothesis Testing and CI

Can you draw a conclusion from combining results of hypothesis testing and confidence interval? For example, here is a fictitious hypothesis test for 1-proportion: Ho = p ≥ 90% Ha = p < 90% ...
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53 views

does p-value distribution indicate the suitability of the statistical test

This post suggests that p-value follows uniform distribution in case of point null hypothesis and continuous data. In my project, I have millions of p-values from actual data. I don't want to get ...
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Hypothesis Testing Fictitious Study Help

I'm doing a self-study on hypothesis testing and have created a fictitious study to facilitate my learning. I just need validation, from you experts, that my thought process on the concepts and ...
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I'm more likely to read “interesting” studies, so do all p-values I read suffer a “readership bias”?

Do I bias p-values simply by reading them — or, more precisely, by having chosen to read the study that contains them? I generally take most p-values with a sceptical pinch of salt. Sometimes ...
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29 views

Effect of Federal Funds Rate on SP500

I have been trying to examine the effect of the Federal Funds Rate on the S&P 500 using regression analysis. Obviously via the graph its easy to see this is a hard relationship to define over a ...
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29 views

Hypothesis testing: t-test and p-value conflict

I am doing a one-tailed hypothesis test on the exper coefficient. My null is the coefficient is not different from zero and my alternative is that the coefficient is greater than 0. I'm using a 5% ...
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Insignificant alone but significant when inclued in multi variate regression [duplicate]

I have a target variable y, two explanatory variables x1 and x2. x1, x2 and y all have zero mean. x1 and x2 has low correlation. y = b1 * x1 + e gives R^2 = 0.6, p-value of b1 = 0.000, out of sample ...
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For a standard normal distribution, are p-values calculated using a $\Phi(-Z)$ or $\Phi(Z)$?

Let $\bar{X}$ denote the value of the sample average for a given set of iid random variables $\lbrace X_i\rbrace_{i=1}^n$. Assume each $X_i \sim \mathcal{N}(0,1)$. According to my econometrics ...
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1answer
51 views

What does it mean if test was rejected less than in 5% cases?

I was reading a paper and authors performed multiple tests for Poisson distribution on single vectors. Large dataset of $n$ quite long vectors was used. The test was rejected only $0.02 \cdot n$ times ...
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Interpretation of Mann-Kendall statistics

I am doing a trend analysis for vegetation dynamics using Mann-Kendall test for trend detection and Sen's slope for computing the magnitude of the trend. There are 6 sites inside a conservation area ...
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35 views

pairwise.t.test in R returning no value

I am a noob in R, and have been breaking my head for the past three hours over the pairwise.t.test in R. My data frame is structured as given below. My data frame has the age of flight of bees and the ...
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Seemingly random results from kstest2 function in MATLAB

I'm trying to understand the kstest2 function in MATLAB so I can use it to check if output samples from two models are from the same distribution. The first thing I did was run a test to make sure ...
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Beta regression model - how to test the model to obtain p values?

I have coral cover data (in percent coverage, thus it is between 0 and 100). I am using the betareg package in R to fit a multiple regression model, where Coral ...
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36 views

What do the four coloured areas of this p-value distribution actually represent? [duplicate]

The chart below shows a distribution of p-values (deep blue and orange areas) given by a data sample that deviates from the null hypothesis, while the grey and light orange areas represent the ...
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71 views

What is the link (discrepancy?) between these PDF/CDF and p-value distributions?

I have created a mixed distribution model comprising 80% $H_0$ plus 20% $H_1$ to illustrate the link between the expected proportions of true and false positives and negatives in the PDF, CDF and ...
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1answer
28 views

Understanding the statistical significance calculated in an experiment

I am trying to understand analysis in a paper which talks about statistical significance of a certain stimulus. I have used 'VALUE' in place of the specific variable that is being observed, and ...
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1answer
59 views

Is it fair to use FDR when the p-value distribution is not uniform under null hypothesis?

One post says that we should check the distribution of p-value before apply FDR correction. If the p-value distribution doesn't behavior well(e.g. U shape, not uniformly distributed at the tail toward ...
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13 views

Degrees of freedom and p-value calculation using contingency coefficient value?

1) I evaluated Chi-Sqr test for 18 rows and 5 columns table. Total Chi-Square value is 128.5 and calculated Contingency coefficient value CC =0.048. Now how to calculate P-value and also how to ...
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8 views

How to obtain a p value from contingency coefficient value

I have obtained a contingency coefficient[cc] value for a table using chi-sqaure. test. Now how do i calculate p value using obtained contingency coefficient value step by step. Kindly suggest.
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In linear regression, how to prove the equivalence of F-test and t-test? [duplicate]

In the setting of linear regression, when we want to test the hypothesis $H_0 : \beta_j = 0$, we can use either t-test or F-test, with test statistics $t = \frac{\hat{\beta_j}}{SE(\hat{\beta_j})}$ and ...
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Statistic test to use for polling study

What statistical method should I use to compare the following polling result? 2 voters examined 7 pairs of side by side images (before and after processing), and voted for image 1, image 2, neither ...
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How can I Infer the proportion of significant data from P-value distribution?

If some of data is generated from normal distribution N(0,1), and some of the data is generated from N(1,1), can I infer what proportion is generated from each by looking at a p-value distribution ...
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2answers
48 views

How can I interpret high p value of a variable in the multiple regression model?

it's a first time I am running regressions for my dissertation and really need your help. I haven't been studying econometrics before, so I don't know if what I am doing is right or wrong. I am ...
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relationship between sample size requirement and resulting p value

If one uses a web-based sample size calculator for a chi square analysis, the resulting sample size seems to have little relationship to the sample size required to obtain significance, eg. .05. For ...
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Is this the solution to the p-value problem?

In February 2016, the American Statistical Association released a formal statement on statistical significance and p-values. Our thread about it discusses these issues extensively. However, no ...
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Nonsensical t-value for level of mixed effect categorical predictor

I have a very unbalanced dataset (102 observations, 26 groups) which I am trying to fit into a mixed effects model. The predictive variables are latitude (continuous) and dominant species ...
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47 views

P-Value for Logistic Regression

I'm currently trying to develop a binary logistic regression (BLR) model. Upon doing the binary logistic regression test in Excel, I arrived with the following results. I want to know which among my ...
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1answer
61 views

p values and significance in RLM (MASS package) R

I'm running some regression analyses and got pretty confused about R's output when it comes to robust regression models. When I run a OLS -- using the command ...