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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Results from logit model using BIOGEME unexpected

I am using BIOGEME to estimate the discrete choice model (choice is made among four alternative routes). I am having hard time with modeling using BIOGEME, and expecting help on this. I have dataset ...
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8 views

ANOVA test mean against predefined constant

How can I calculate the p-value (statistical significance) if my hypothesis asks for specific mean values? I suppose this can be somehow calculated using ANOVA, but I could only find examples where ...
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17 views

Evaluating correlation of 2 time series

I did some research on this website and I found a few questions about correlation between 2 time series. However, all of them end-up with cross-correlation as answer, which is not really what I want. ...
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13 views

GLMM test P-value and inference

I am analyzing results of my artificial predation experiment using GLMM (glmer in R) where response variable is count and predictor variable [a-categorical factor with 2 level;b-categorical factor ...
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0answers
32 views

Spearman's rank correlation has p-value zero?

It looks like R's cor.test returns p-values of exactly zero if the real p-value is very low. For example: ...
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2answers
93 views

Why reject, not accept $H_0$ when $p$ value less than $\alpha$? [duplicate]

Let's say ABC drug company claims their medicine cures 90% of patients. Now a doctor conducts a trial by taking a random sample of 15 patients. Result shows 11 of them are cured but 4 are not. In ...
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0answers
15 views

How do I calculate a t-score from a p-value (gain scores and N also available)

I have this problem that only the gain scores with the p-value of a t-test are given in a scientific article. The authors neglected to report the t-test statistic and I'm stuck on figuring out how to ...
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1answer
31 views

Can I get an Odds Ratio (or other effect size) from two proportions and a p-value?

I am conducting a meta analysis that is comparing dichotomous outcomes for two groups. So for each study, I have the proportion of the outcome for both groups and the sample size of each group, and I ...
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1answer
26 views

Scientific P Value with adjusted R Square [duplicate]

I am running Spearman correlation between 2 variables weight and freight both being numeric. The output I have received from correlation is P value - 0.00E+000 and Rank R Squared is 0.61 and which ...
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47 views

Embarrassingly easy stats question

I have a large set of values (1000) that are each a measure of accuracy for a large set of corresponding models that were generated using random data. I want to compare a single measure of accuracy, ...
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2answers
43 views

P-value vs Type 1 Error [duplicate]

I am trying to understand the relationship of a p-value vs Type 1 error rate. My understanding of one interpretation of a p-value is the following: "the p-value tells us the probability of making a ...
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1answer
10 views

calculating significance of common genes from different comparisons

we are having difficulties calculating the significance of our between-group comparisons. We did multiple differential expression Analyses of different time-points and mutations. We analysed the ...
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1answer
32 views

How to correctly combine p-values?

I have multiple individuals, for whom I collected two time series of some parameter. For each individual, I calculated, whether these time series are correlated. So, if I have 20 individuals, as a ...
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1answer
30 views

Correlation Analysis of Standarized Testing Data

I need some insight on how to correctly analyze some data using correlations. The nature of the data and research endeavor is as follows: I have two independent samples of different sizes that ...
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3answers
66 views

Type of p value to select from those given by software

I'm a medical student and pretty new to statistics, struggling with some things. I am currently undertaking a research project on dilated kidneys in foetuses and the outcome in childhood. I have some ...
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11 views

Analysis of PValues Matrix

in clinical environment I'm setting up a model to identify fraudolent behaviours from specific sites, calculating for each site some aspects that could lead to a p-value (this approach is based on a ...
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45 views

Statistic test ( t-test )

I have 4 methods(4 solutions for one problem). Each of these methods were tested over multiple data sets(5 data sets) and the F-score values were gained for each method over each data set. I am asking ...
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3 views

how to accept or reject hypothesis based on asymp.sig [duplicate]

i just wanted to know how to accept or reject null hypothesis based on chi square value obtained in spss null hypothesis is no influence on celebrity endorsement on consumer buying behaviour ...
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16 views

Dickey-Fuller Test

I am very new to R, and am really struggling to interpret the results. This is for the CHF-USD exchange rate returns for 1999-2015. What is the "cut off" % the ADF test uses, so when can i reject the ...
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Scipy.stats.anderson_ksamp negative return values for test statistic

Ok, so I've been trying to run this test on the the iris dataset to see if it flags the clusters within the data as samples that aren't from the same population. from sklearn import datasets iris = ...
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1answer
68 views

Finding p-value based on Poisson Distribution

I'm having trouble understanding my homework that involves p-values. Here is the context of the problem before I discuss the processes I've gone through: Suppose a company which produces fire alarms ...
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4 views

Backwards stepwise regression approach in Stata 13 [migrated]

I am attempting to perform a backwards stepwise logistic regression analysis in StataIC 13, and I am not sure what I'm doing wrong, but the software is not eliminating variables with p-values < ...
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26 views

Generating t statistics from p values - binomial test multiple comparisons

I am using the binomial test to generate a series of p values. However, my method of multiple comparisons correction that I wish to apply to this series requires that I also have the corresponding t ...
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20 views

Bonferroni correction of bootstrap generated p values

I have run a multiple regression analysis with 900 independent variables and bootstrapped this analysis 1000 times, with replacement, to generate bootstrap p values. When I looked at the results, I ...
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1answer
85 views

Model selection and performance evaluation with different sample sizes

Suppose there are K experimental units. Each unit is associated with its own dataset consisting of 400 observations. For each unit, we set up a two-sample test, 200 vs 200. Because of a large sample ...
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24 views

How to compare 2 sets of p-values?

I have 2 sets of p-values, each set containing 100 p-values from results of 2 different methods doing the same job. If I had only 1 p-value, I could have just basically said that the method achieving ...
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35 views

Need a method for determining variable groupings in R

I am using R and trying to group one of my variables into larger groups so they have credibility. I have been manually setting each factor of the variable as the reference level, looking at all other ...
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1answer
52 views

How to make a two-tailed hypergeometric test?

I am talking about a hypergeometric test but the logic probably applies as well to the binomial test (and other similar tests). Basic Scenario I have a population of $n+m$ balls in an urn. There are ...
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1answer
68 views

KS Test and Wilcoxon Rank Sum Test, large differences in p values

I am relatively new to non-parametric tests. I wrote the following R code to test 2 sample tests using the KS test and the Wilcoxon Rank Sum test. Drawing 2 samples of various sizes from unit Normal ...
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1answer
40 views

Interpretation of P values in Genome Wide Association Studies

Genome wide associate studies (GWAS) are a common method used in associating single nucleotide polymorphisms (SNPs) to a disease or trait under study. I don't work in this field and I'm always ...
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1answer
29 views

Definition of p-value in carets confusion matrix method

In the documentation for the confusion matrix method in the caret package, the p-value is described as: a one-sided test to see if the accuracy is better than the "no information rate," which is ...
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1answer
44 views

Why exactly is normality an assumption in a T-test but not a Wilcox rank sum/Mann Whitney U test when obtaining a p-value?

In addition to the question, please do correct anything below that I have incorrect. I understand how the test statistics for a t-test and WRS/MWU test are calculated. In a t-test, $t=\frac{\bar ...
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20 views

p-value inside r for Tableau

First - I am not a statistician. Please be kind. :) I have received a requirement from my stakeholders to show a p-value between two values. We use Tableau to show our analysis and are told that we ...
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3answers
58 views

finding p-value in pearson correlation in R

Is it possible to find the p-value in pearson correlation in R? To find the pearson correlation, I usually do this ...
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13 views

Significance level in terms of modeling error

Let's imagine I have a regression model with numeric output or a binary classification model with probability output (probability of a sample to belong to class 1). I predict values for pairs $A_1$ ...
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12 views

How to calculate the probability of a sample to get a specific pattern, given all samples and features?

I have a data aggregation tool, which collects information on many samples (clusters of molecules in this case). So it can create a sparse matrix of NxM binary values (N answers of 0 or 1 for M ...
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1answer
176 views

Distribution of p-values - Binomial test

I heard that under the null hypothesis the p-value distribution should be uniform. However, simulations of binomial test in MATLAB return very different-from-uniform distributions with mean larger ...
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1answer
69 views

Bonferroni Correction for Post Hoc Analysis in ANOVA & Regression

As we know, if we are doing many tests or multiple comparison, we don't use the same $\alpha$ value and use some $\alpha$ correction methods like Bonferroni. This is done because when we do multiple ...
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1answer
58 views

Fisher's exact test vs chi-squared

I've been trying to figure out the correct way to calculate the p-value for my data. I originally created a simulation that randomly selected numbers that were greater than or less than a certain ...
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1answer
35 views

Hypothesis testing on an empirical distribution

This may be a basic question, so please pardon me: given a vector of univariate data, and an individual observation from the said univariate data, I would like to derive some probability of observing ...
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1answer
96 views

Cox Regression p-value

I am using R's flexsurvreg function (in the flexsurv package) to fit a AFT model to my data. This is the line of code that fits the model to the data: ...
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1answer
32 views

What p-value threshold should I use for many-variable probit?

I have a probit with 7,000 observations and 120 dummy independent variables, of which Stata omits 31 because of low n and 2 because of collinearity. I also have a set of five dummies to make a time ...
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1answer
61 views

Calculate p-value in a two sided Fisher test

I'd wish to know how is calculated p-value in a fisher.test using as alternative hypothesis a ...
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17 views

LME, t-test and glht

I am doing some light simulations, but came across the following problem. I cannot obtain the same p-value as a paired t-test as it does for multiple comparison and LME. ...
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56 views

Heatmap small p-values

I'm experiencing some difficulties trying to manage too small p-values derived from a Fisher test. In particular I have p-values like: 2.220000e-121, 1.260000e-26, 1.260000e-334, and so on. The ...
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1answer
63 views

Bonferroni Correction p value in SPSS [duplicate]

I have run an analysis on data using SPSS. I have a repeated measures design with 7 conditions. I chose to do pairwise comparisons to see where the effects lie and used the Bonferroni correction. If ...
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1answer
47 views

How to replicate this P-value given $r$ and $n$?

I am using http://www.socscistatistics.com/pvalues/pearsondistribution.aspx as my reference here. $r = 0.0789$ $n = 15$ The $P$-value is $0.779858$. I have tried to replicate it without success. Is ...
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26 views

P value validity

I have done a statistical analysis in DNA methylation data, I already wrote my report, but it got rejected by my adviser as he wants me to do some changes in the paper. One question I couldn't answer ...
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Correcting for p-value for “frequentist” sampling methodology

I have a regression of the form: $$ Y = \alpha + \beta_{1}*X_{1} + \beta_{2}*X_{2} + \epsilon $$ There are a few subtleties, however, that cause me to suspect the p-values are artificially low. ...
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1answer
32 views

Analysing data from summary table on R (interactions)

If I want to test whether data[,1]:setB is equal to 0 or not, do I just use the given t value and p value or do I need to add it with the data[,1] values? looking at the p value of data[,1]:setB, I ...