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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Confused about when to use z-test and p-value test for hypothesis testing
Can anyone help me solve this confusion? I don’t know why z-test and p-value test for hypothesis testing is used for this, given that the pattern between the two questions are same.
Records show that ...
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p-value for results of sub group analysis with ML?
I developed a ML algorithm (Xgboost) to predict a target in my data set.
I obtain here the results of my predictions on my test set :
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Large sample size and small subpopulation of interest - what is the impact on p-value
Let's say I want to compare the life satisfaction of horse owners (approximately 5% of the sample) to dog owners, and I have n=10,000. In another context, I would say I have a very large sample size, ...
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Application of binomial probability to sequence matches
I'm searching for the number of matches of a three nucleotide sequence (GTG) in a window of 9 nucleotides located at a certain position in a large number of DNA fragments. I want to answer the ...
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Is the empirical coverage rate of a confidence interval equal to the test's acceptance rate for a correct estimate (in a simulation study)?
I am conducting a simulation study to assess the performance of several confidence intervals.
My approach is to simulated (N = 10000) datasets, estimate the parameters, construct a confidence interval,...
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How to correct deflated p value distribution from qqplot in PWAS/GWAS
I'm conducting regression analysis using R of the ability of several hundred proteins (and other covariates) to predict ventricle volume in a human sample. As is common in GWAS/PWAS research, I ...
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What is the null hypothesis and p value in the lagged autocorrelation of innovations in Kaman filter
I am using statsmodels.tsa.stattools.acf to calculate the lagged autocorrelation of innovations in Kalman filter with alpha=0.05....
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Combined p-value from wilcoxon test result on control experiment - interpreting the null-hypothesis correctly
EDITED
I spotted error in my code, and now results are no more contradictory. But still I keep the question for utility of others and myself in understanding meta-analysis and correctly interpret null-...
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Difference in results between anova and Anova (car)
I have a question about using the anova function and Anova from the car package. I know there is a question about Type 1, 2 and 3, but the question is this: I am doing an analysis where I want to ...
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Appropriate test for checking signifigance in learning
I have conducted research as to if problem based learning is effective in language acquisition.
I have a set of 6 questions used in a pre and post test
There was a control group and a test group.
So ...
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Is one-way ANOVA + Tukey HSD a good choice for significant test for data with different orders of magnitude?
I'm here to receive some information regarding the application of a statistical test of significance for this type of data.
The example shows the values of the peak areas of a given cocoa molecule ...
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Easy Fisher Exact Test on multiple runs
I have a binary classifier problem with 18 samples to evaluate. To have less variance, I ran the same experiment 3 times, so I have 54 predictions.
Now I want to run a Fisher Exact Test, but is it ...
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Transformation of negative reaction time values?
I am looking at the difference in mean reaction time change between 2 populations. Although I subtracted the new reaction time from the original(there was mostly a reduction in reaction time across ...
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Two sided p-value for a discrete distribution is greater than one
Suppose $X_1$ is a random variable. I want to test the hypothesis $$ H_0:X_1\sim \delta_0 \textrm{ vs } H_1:X_1\not \sim \delta_0.$$
Where $\delta_0$ is the Dirac-measure in $0$. As teststatistic I ...
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Could you recommend a textbook for t-test and p-value?
I am a graduate student and now I have a trouble to understand p-value. I watched youtube videos, but they didn't really help. I want to know it a bit in depth. Could you please recommend a book for ...
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Any meaningful interpretation t-distribution, when rescaled using the sample SD?
To visualize p-values or confidence intervals, the t-distribution is sometimes rescaled using the sample standard deviation and then centered at a certain value.
To be more specific, consider drawing ...
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Combine p-values of several independent samples for combined hypothesis
I have a dataframe with 4 columns, corresponding to different emotions extracted with ML methods from one video. The dataframe describes one person, rows represent moments in time. Now I'm trying to ...
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Can inferences be made by comparing t and p values?
After running my regression, none of my variables are significant so I was wondering if conparing t and p values could be a source of discussion instead...
If so, can anything be inferred when a t ...
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How to interpret a 95% CI: 1.00-1.00 with a p-value = 0.004
I am performing a missing data analysis from a modified (the original data has been modified for the purposes of teaching) Randomised Control Trial.
The missing variable of interest is "prior use ...
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Clarification of one sided vs two sided p value following permutation testing
I am unsure as to how to compute a two sided p value following permutation testing, following different examples online.
For example, this post Two-sided permutation test vs. two one-sided, gets the ...
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R function to calculate the p-value
For a dataset with mean = 67 and the standard deviation = 6, how could I find the p-value associated with the true population mean being 79 OR greater in R?
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I'm struggling to understand how, in an categorical multiple regression, adding in a continuous variable can change the beta p-values
So I ran a regression with an outcome variable (CSI) and a categorical predictor variable (RT) than has two levels (A and B). I made A my baseline variable, and found that the difference between A and ...
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Calculating p value using Bootstrap in R for nonparametric test
Im trying to approximate the p. Value using bootstrap in R by boot function
But in the result is repeated i.e the values of t0 ….tn are the same so the p value is zero !!!!! I don’t understand why ...
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A question about Adjusted P-value
I have five independent variables and one dependent variable. If I apply the univariate analysis between each independent variable and dependent variable before running the multiple regression, do I ...
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How do we report significant tests without p-values? Reliance on confidence intervals
I'm pretty much reporting these results. I've bootstrapped my sample using lmersampler, which does not provide p-values for bootstrapped models. I relied on confidence interval boundaries to justify ...
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Three way ANOVA - very small p-values. Is my data normal?
I have a data set with three groups: {Hi, Low}, {Drug amount 1, Drug amount 2...}, {Time 1, time 2, Time 3...}
The dependent variable is a percentage, which I have log transformed (as the distribution ...
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Can I use a p-value as my decision threshold estimate when calculating AUC-ROC?
Sorry if the title is confusing. I essentially want to know if it's appropriate to use a p-value as the decision threshold (of the null outcome) when calculating AUC-ROC. I have a dataset of outcome ...
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Probability of a point being from the same distribution as sample
I have a sample of two-dimensional points $\{\{x_1,y_1\}, \dotsc, \{x_n, y_n\}\}$, I've built a linear regression line, there seems to be a correlation between X and Y (Pearson's 0.662 if that matters)...
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How to test if users remain consistent in their preferences?
I am unable to find a suitable way to statistically test the hypothesis that users remain consistent over time in their preference for various product attributes. The three product attributes whose ...
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Calculate significant genes from significant level
If I know that in a study a total of 2936 associations reached a given statistical significance level (P < $6\times 10^{-11}$) and that the total number of SNPs analyzed that belonged to a specific ...
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Significance of the p-values of the parameters in a non-linear model (using R)
I applied a logistic regression using the nlmrt package to describe the relationship between biomass and the distance and site variables. I got this result, but I ...
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Finding the p value of Generalized Likelihood Ratio (GLR) test
In doing a subset test of $H_0: \frac{d_1}{a_1} = ... = \frac{d_{10}}{a_{10}}$ vs $H_1: $ no restriction,
where $d_i$'s are parameters and $a_i$'s are known constants
Suppose a generalized likelihood ...
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Comparing apples and pears interactions in repeated measures anova
Suppose I'm running a 3x3 repeated measures ANOVA with the main effects of "Condition" and "Species": Condition (hat x neutral x glasses) Species (dog, cat, human). The experiment ...
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Does the high frequency of a dummy variable make it seem it is significant?
Looking at IMDb scores (dependent) and movie genres (independent), and coding genres to binary dummy variables (action yes=1, no action=0, drama yes=1, no drama=0, etc.). Dramas are highly popular ...
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Understanding the computation of p-value and its v-test by catdes() of FactoMineR
One of the functions that helps to characterize clusters is the catdesc() function. The output of this function is very informative giving the following bits of information:
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From Wald test statistic to P-value
Lets say I have a dataset with a binary target variablem, smoker / non smoker, and a continuous variable of miles running per week.
So for each catigory (smoker or <...
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R wilcox test result conflict
I have gotten R Wilcox test results I do not understand. Comparing two non-Normal independent sets of ~500 ages. The p-value ~.17 but results is "alternative hypothesis: true location shift is ...
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Why do type 3 tests give different results than GEE for a binary predictor in SAS
I'm using PROC GENMOD in SAS to model a continuous outcome as function of flight which is binary (1=yes, 0=no) and a categorical predictor (ethnicity.) So I ask PROC GENMOD to output type 3 statistics....
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Need help explaining Bayesian p-value plot
I'm working through Chapter 2 of BMCP and am having trouble understanding why the plot of a Bayesian p-value looks so unexpectedly "spiky" or multimodal. Here's my code
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The number of sample size in this case
I'm trying to compare three conditions (A, B, C). And I have a question about the sample size in this experiment.
There were 27 participants, and each participant listened to 20 songs for each ...
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P-value Computation in Quantile Regression
How can be the p-values be computed in quantile regression?
I can see pre-existing packages in R(quantreg) and Python(statsmodel) arriving at the p-values in Quantile Regression.
Kindly provide ...
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Can I use a threshold to avoid 0 p-values
I have many kmers counts from different prokaryotes, and I use a high markov order to obtain the expected counts to compare with the observed counts. And for look for over/under represented kmers ...
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Should a contingency table be "symmetric"?
Im am running a fishers exact test on some data but im unsure of how the input contingency table should be formatted.
Option 1
...
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What is hypothesis testing one sample one sided?
My goal is to learn hypothesis testing one sample one sided. Honestly, I don't get it.
Hypothesis testing one sample RIGHT SIDED
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ANOVA with quantile regression: interpretation
I asked a related question on how to figure whether multiple models are significantly different or not.
To compare two models using anova in R, I can simply use <...
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Goodness of fit - Large deviation
The Pearson test (chi test) provide a mean to evaluate whether a given sample (empirical distribution) match the theoretical one. The test compute the p-value, which is the probability for seen the ...
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One-sampled t-Test: large Cohen's d and large p value (is there a statisctical error?)
The p-value from a t-test I have run is unexpectedly large, considering Cohen's d.
I calculated the one-sample t-test in RStudio for the following hypothesis:
H2: For athletes who have already reached ...
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Can you use power analysis to find if the null hypothesis is true rather than not?
So in power analysis I have only ever seen it explained like in this statquest video:
https://www.youtube.com/watch?v=VX_M3tIyiYk
Where you have two distributions and you're trying to see if they are ...
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Statistical Test for showing variance in peak values of two different populations?
I am publishing a paper and one of the reviewers requested that I provide a statistical method to show the difference between peak values (peak value = tallest bin in a histogram) of two populations. ...
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Test whether a sample (which is a 1D array of values) comes from a population (2D array of values)
I'm taking samples in such a way that I record multiple discrete values for each sample. Given an instance of a sample, is there any way to test if this sample appears to "fit" the ...
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