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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how do I “build” a distribution from a list of values and then calculate p-values?

I have a list of values (A) that I consider to be the null distribution which I want to use to test the significance of another set of values (B) and get p-value for each item in B. I read this post ...
491 views

Afex does not give me all p-values of all parameters. What should I do?

I have installed the package afex with this formula: ...
236 views

pvals.fnc does not work with random intercept and slope. How to get p-values?

I am doing LMM in lme4, and have installed languageR to run pvas.fnc(), but it does not work with random intercept and slope. This is the message: ...
68 views

review papers on P-values, adjusted P-values and common statistical tests in bioinformatics

I'm looking for review papers which give comprehensive reviews of P-values, adjusted P-values and common statistical tests in bioinformatics.
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Adjust p-values for variance inflation factors

I'm fitting linear mixed models and I have slightly inflated p-values due to multicollinearity. I deleted the factors with the highest VIFs until none of them was larger than 3. The VIFs tell me, ...
1k views

Bootstrapping regression slopes - p-value and significance level

I have a data set showing an (exponential) increase in the size of an animal population over time. I can fit an exponential model to these data and obtain an estimate of the population growth rate (...
146 views

Is p-value involved in Neyman-Pearson Testing procedure?

It seems to me that, after having a predetermined level of significance, the Neyman-Pearson approach only requires to see if the observed x lies in the rejection region or not. In this case, how to ...
42 views

Combining the Counts and P-Values

I have experimental and computational data for n genes in data matrix. The rows are the genes and columns are its values. Now, the data is from two sources: Computational Prediction Results in form ...
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Is this a valid test?

I have 5000 cases vs 5000 controls with positive/negative outcome. chi.test shows no significance for this data. I get significance when subsetting cases on VarX, ...
999 views

How to get the P-value from a known Friedman's chi-squared value

Provided I have the value of the Friedman's chi-squared statistic, is there any way to get the corresponding P-value without copying the whole table of critical values in my Python program?
426 views

Exact p-value for any nonparametric test

After having found the R-package coin, I have a question. For example, to get an exact p-value, I could use the function ...
89 views

One sided p value in a crossover trial

A test treatment was compared with the control treatment in a cross-over trial with 10 patients. The test treatment was superior in 8 patients and the control was superior in other 2 patients. What is ...
113 views

Which value is the p-value?

It's a right-tailed Population Proportion test. The critical value is 1.645 and the calculated test statistic is -1.14. The area from minus infinity to -1.14 is 0.1271. The question is, since it's a ...
885 views

Two-sided p-value of Fisher's exact test

For a paper I'm using Fisher's Exact Test in R. As I already found out the p.value in R is calculated as the sum of all probabilities of the hypergeometric distribution with the given parameters lower ...
13k views

P value for a negative Z score?

I am new in this and am hoping for some assistance.I have the table(attached) and need to calculate the value corresponding to Probability(-2.026). Can someone help me how to look at it from the table ...
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Stepwise variable selection, significance and interpretations

I have read that the p-values of the variables resulting from a stepwise regression are smaller than it should be. So, suppose there are two independent individuals trying to address some problem. ...
922 views

(Dis)Advantages of correlation vs. $R^2$ vs. p-value of linear regression for two variables?

I would like to know what are advantages and disadvantages of $R^2$ vs. correlation (e.g. cor() in R) vs. p-value of linear regression for two variables/features? ...
3k views

Getting 1-tailed p value from a 2-tailed p value in SPSS v23

For the purpose of my research, I use IBM SPSS and would like to get paired t-test result with a 1-tailed p-value. This video states how to derive a 1-tailed p-value from 2-tailed p-value, however, ...
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I have a t-statistic of -1.06 how do I find the p-value by hand?

I keep seeing this in my econometrics book. "The t-statistic is -1.06 which is not significant at even the x% level against the two-sided alternative". This happens at exercises for which I have to do ...