In hypothesis testing, the $p$-value refers to the probability of seeing a result as extreme (or more so) than the one observed, given that the null hypothesis is true. When the $p$-value is small, then there is good evidence that the null hypothesis is false, since it would make the observed data ...

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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 ...
2
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1answer
21 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 ...
2
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1answer
42 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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15 views

How do I compute the F values, p-value, and degrees of freedom for this experiment?

My lab group tested whether sowbugs gravitate towards the tepid, hot, or cold side of a dish. We checked distribution of bugs when it was tepid, when one side of the dish was heated, and when one ...
0
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1answer
25 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
68 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: ...
2
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1answer
24 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 ...
0
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1answer
24 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 ...
0
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12 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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37 views

Confidence interval or p-value? [duplicate]

I am working on an assignment and struggling with odds ratios and confidence intervals. I have the following data from a fairly dubious study about shift work and poor sleep quality: OR 1.2 95% CI ...
0
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0answers
41 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 ...
2
votes
1answer
41 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 ...
0
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1answer
45 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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25 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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27 views

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. ...
0
votes
1answer
25 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 ...
0
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0answers
31 views

P-value F statistic test [duplicate]

I want to calculate the p-value from a two-sided test using f distribution function in R, but I don't know how t do it. I've tried with some tutorials, but it doesn't work.
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17 views

Interpreting p-values of log regressions

The following output is for a log log model. ...
0
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1answer
36 views

Statistical significance [duplicate]

What does it mean a value is statistically significant and when does it occur? For example, at a 5% level of significance, do p-values above or below 0.05 indicate significance?
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19 views

How to interpret p-values on log log model?

If the p-value of log(independent variable) = 0.0023 for the hypothesis that the independent variable=0, how do I interpret the p-value? Does this interpretation change if this was a simple linear ...
0
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0answers
61 views

Is this good statistics?

I have the mean of 2 samples, as well as the standard deviation. I wanted to see if I could run a t-test on this data, and using the standard deviation and my knowledge of the 68–95–99.7 - I did the ...
0
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1answer
31 views

Which of the following when performing a statistical test is NOT a Random Variable?

For a test for my stats class, we were asked, "When performing a statistical test on a sample, which of the following is NOT a random variable?" A) The Test Statistic B) the p-value C) The power of ...
2
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1answer
37 views

Are there test statistics for which a larger sample size does not tend to produce a smaller p-value?

I'm assuming that there is a genuine population effect. By test statistics I mean test statistics that are in accepted use, and not a hypothetical test statistic that a reader might simply make up. ...
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6 views

Discordant significance of OR’s confidence interval and p-value in glm(quasibinomial) model [R]

I’m currently trying to test if differences in proportions of people infected by malaria (RDT positive) between clusters with high or low coverage of control intervention are significant. Therefore ...
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37 views

What´s the difference between the p-value and interaction p-value?

I need to interpret the logistic regression data shown in the figure. Q1-4 represent continuous values of height measurements divided into quartiles. The covariate is mean weight. Can you tell me what ...
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0answers
68 views

Delta Method to Compute Standard Errors of Transformed Variables

I am estimating a a finite mixture model to identify proportions of four behavioral types using an experimental dataset. This dataset has data for 500 individuals and each individual has 30 tasks. In ...
0
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0answers
25 views

WinBUGS/JAGS code for calculating Bayesian p-value from negative binomial model

I have a working negative binomial model written in BUGS code, but am not sure about the appropriate Bayesian p-value code to test goodness of fit. Specifically, I would like to calculate Pearson's ...
0
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1answer
45 views

Making the most of Standard Deviation and P value — graphing?

I have a question or two in regard to getting the most out of the statistics of my data. By way of background, my qualitative observations of two distinct populations that are uniformly regarded to be ...
6
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1answer
77 views

How to respond to reviewers asking for p-values in bayesian multilevel model?

We were asked by a reviewer to provide p-values as to better understand the model estimates in our bayesian multilevel model. The model is a typical model of multiple observations per participant in ...
0
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1answer
41 views

Reporting pseudo p-values for bootstrap-estimated linear regression coefficients

I've just received peer reviews for an applied paper that reported a table of multiple linear regression coefficients. While I reported 95% confidence intervals for these coefficients, a reviewer has ...
25
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5answers
427 views

How should an individual researcher think about the false discovery rate?

I've been trying to wrap my head around how the False Discovery Rate (FDR) should inform the conclusions of the individual researcher. For example, if your study is underpowered, should you discount ...
1
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1answer
30 views

How can I avoid misidentification of a exponential distribution as Gamma or Weibull?

I'm trying to write a piece of code in R that identifies a set of sample data as belonging to a specific distribution and pull the specific distribution parameters, by performing the K-S test and ...
1
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3answers
67 views

Highly significant Pearson's chi-squared test (goodness of fit) when observed & expected are very close

I have two arrays that I would like to do a Pearson's chi-squared test (goodness of fit). I want to test whether or not there is a significant difference between the expected and observed results. ...
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93 views

One-sided significance test for correlation

Let's say you have data from two random variables $X$ and $Y$, and the two random variables are highly correlated (ex: $r=.97$). The p-value, which is testing the null hypothesis that there is no ...
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1answer
21 views

Does rejection of null hypothesis ($p < \alpha$) for one representative sample imply rejection in a different sample?

I am new to hypothesis testing so forgive me if this has already been asked. Suppose that I've already decided on a null hypothesis with a significance level $\alpha = 0.05$, then obtained my ...
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3answers
62 views

How to use an optimization solver to get t-stats and p-values for the estimates?

I calculate a data log likelihood (evaluated at a set of parameters to be estimated), and my task is to find the set of parameters that maximize my log likelihood. My problem is: thought there are a ...
0
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0answers
11 views

Statistical Comparison of two different waves

I have two waves data for a couple of cities and I need a comparison W I W II City A 10,000 10,100 City B 200 202 City C 1500 1515 There is a 10% increase of ...
2
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2answers
241 views

Statistically significant?

I am new to statistics and so any help would be greatly appreciated! I have done a study looking at the number of samples being sent to the lab for patients with UTIs in a GP practice. I then ...
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0answers
23 views

How is p-value performing as a measure of association?

It's known that Cramér's V (Chisq adjusted for table dimension and sample size) is a good measure of strength association. But what about the p-value? P-value (as a probability of the numbers we have ...
2
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2answers
36 views

How should I interpret a Spearman's rank correlation significance of zero?

This is a follow up to a Stack Overflow question I'm calculating the Spearman rank correlation coefficient between two vectors using corr in Matlab. The two ...
1
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2answers
378 views

Still confused with the p-value definition

The p-value is defined as the probability, under the assumption of the null hypothesis H, of obtaining a result equal to or more extreme than what was actually observed. A p-value lower ...
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10 views

Compute a Pvalue from the averaged Pearson and Spearman rho

on the one hand, Pearson correlation is sensitive to outliers, while Spearman is not. On the other hand, if you have quantitative data, Spearman will treat it like ordinal data. How about averaging ...
2
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0answers
14 views

Expected p-values from a series of trials

I'm looking at this toxicology study (http://www.sciencedirect.com/science/article/pii/S0041008X1500085X). The study has a negative control group, a positive control group and three treatment groups ...
1
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1answer
80 views

No significant tests when using Benjamini-Yekutieli multiple testing correction on millions of tests

I am using a univariate filter to reduce the number of features prior to applying a learning algorithm to a huge binary classification dataset (22510066 features x 500 examples). All the features are ...
0
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1answer
21 views

Obtaining test statistic for problem with two populations

Given a sample population of 54 men and 61 women, I want to figure out whether or not the average male spends less time during his daily shower than the average female spends during hers. The average ...
3
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1answer
87 views

P values of coefficients in rlm robust regression

I am using rlm robust linear regression of MASS package on modified iris data set as follows: ...
2
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0answers
12 views

Hypothesis testing: 95% confidence intervals of group means overlapping zero or 83% confidence intervals?

I am trying to select between the following two methods to look for significant differences between two abundance estimates: 1) calculation of the 95% confidence interval for the difference between ...
0
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0answers
23 views

Standard multiple regression and multiple dependent variables. and bonferroni correction?

I have a question regarding running multiple regression equations with multiple dependent variables. Three independent variables and 3 dependent variables. A colleague advised me to conduct three ...
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1answer
63 views

Help with HW questions

I have two following questions I could not really decipher how to get the P-Value. Data from a recent year showed that 71% of the tens of thousands of applicants to a certain program were accepted. ...
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16 views

p-test for parameter

Statisticians, number magicians, I was wondering what the best way is to check for the equality of two parameters including possibly a confidence interval and p-value. $$H_0:\beta_1=\beta_2\vert\ ...