Data Science Stack Exchange
Data Science Stack Exchange

Questions tagged [pvalue]

12 questions
4
votes
2 answers

how do I calculate p-value?

I need to calculate statistical significance of difference between two time series, each with 4500 terms. My null hypothesis is that $H_0: \mu=\mu_0$. How can I calculate p-value? Is Z-statistic useful for p value calculation? How to get p-value…
nick_name
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2
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2 answers

p-value and effect size

Is it correct to say that the lower the p-value is the higher is the difference between the two means of the two groups in the t-test? For example, if I apply the t-test between two groups of measurements A and B and then to two groups of…
HelpNeederStudent
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1
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0 answers

Levene test for equal variance

I would like to run one-way ANOVA test on my data. I saw that one of several assumptions for one-way ANOVA is that there needs to be homogeneity of variances. I have run the test for different data-sets. I find sometimes my p-values are larger than…
Reut
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1
vote
1 answer

T-test against normalised or standardised data gives different results

I am studying the problem to predict popularity of a tweet, and want to test null hypothesis: there is no relationships between favorite_counts and another set of variables, like number of friends of users. I am not sure if normalise or standardise…
user305883
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1
vote
1 answer

Low P value in Chi-squared test but low coefficient in logistic regression

I ran a chi squared test on multiple features & also used these features to build a binary classifier using logistic regression. The feature which had the least p value (~0.1) had a low coefficient (=0) whereas the feature which had a higher p value…
user16584277
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0
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1 answer

Multiple Hypotheses in python

I want to write a method to test multiple hypotheses for a pair of schools (say TAMU and UT Austin). I want to consider all possible pairs of words (Research Thesis Proposal AI Analytics), and test the hypothesis that the words counts differ…
stacky
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0
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0 answers

Do we need to apply "multi-testing" corrections for the p-values in a regularized model?

Say we are fitting a penalized model, such as a linear regression with lasso regularization. We expect to obtain a model with the most significant covariables. The method starts with many covariables and ends up with just a few, as we use to do with…
skan
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0
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0 answers

A/B test results don't hold in hold-out dataset

I'm working on a project consisting in analyzing some game data. The game consists of two players competing between them. The result of the game is either win or lose. Players can choose from different initial positions. My objective is to analyze…
alexmolas
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0
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0 answers

Different runs of One Way ANOVA give different results in Python (on the same data, using stats.f_oneway)

I wrote the following code: The data I am running this code on is randomly generated, but I use fixed seeding. Each time I run the code this function gives different results for F statistics and pvalue. What is the reason for this? Is this normal?…
Archil Zhvania
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0
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1 answer

Statistical significance in multiple groups

What is the most appropriate test to validate significance in the case I'm comparing multiple different groups? e.g. I have different groups of ages (teenager, young, adult, elderly) and a conversion rate related to each of them in my website. How…
simon
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0
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0 answers

P value calculation for stacked LSTM model for binary classification

I need to calculate the P-value for a stacked LSTM model. Does that mean that I need to run the model multiple times and consider the null hypothesis that the model's accuracy is almost the same across the multiple runs? if not can you please help…
Ahmad Ayyad
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3 answers

p-value of chi squared test is exactly 0.0

I need to do a chi square test of two of my dataset's categorical variables. This two variables have basically the same meaning but comes from two different sources, so my idea is to use a chi square test to see how "similar" or correlated, these…
Michele Papucci
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