# Questions tagged [statistical-significance]

Statistical significance refers to the probability that, if, in the population from which this sample were drawn the true effect were 0 (or some hypothesized value) a test statistic as extreme or more extreme than the one gotten in the sample could have occurred.

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### Comparing countries with different proportions of available data and missing values

I have 200 countries, and each country has various subcategories with different number of data points and missing values. For example, I have a country with 100 data points, 40% of which are missing ...
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### Can I investigate the simple main effects of a factor with multiple one-way ANOVAs if the main effects (from two-way ANOVA) were insignificant?

I want to analyze the results of an experiment that was conducted as a 3 X 3 balanced, repeated measures study. There are two factors in my design--let's call them Factor A and Factor B. Both factors ...
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### Hypothesis Testing in Logistic Regression

In Linear Regression, the book Introduction to Statistical Learning argued that we should use the $F$ statistic to decide if s $\beta_1 = \beta_2 = ... = 0$ instead of looking at individual p-values ...
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### Pros and cons of using a ratio vs a difference score to compare group means

I plan to collect data from 2 groups of people (Gp_1 and Gp_2), some few hundred people in all. Each person will respond to 100 yes/no tasks, each response yielding both accuracy and reaction time ...
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### Insignificant terms in a regression model

Is it okay to include insignificant terms in the regression model if it increases the $R^2$ and lowers the residual standard error?
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### Why does my forest plot say a study's result is statistically significant when it's not?

A large amount of computing resources is required to compute exact probabilities for the Kruskal–Wallis test. Existing software only provides exact probabilities for sample sizes less than about 30 ...
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### Opinions on a statistical error in p values (re: standard deviations, t-test/Kruskal-Wallis) in a published study? [closed]

A large amount of computing resources is required to compute exact probabilities for the Kruskal–Wallis test. Existing software only provides exact probabilities for sample sizes less than about 30 ...
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### Combining P-Values from multiple trials of the same experiment

this is my first question here, a little background about me, im a biomedical engineer, im studying a PhD in Neuroscience, and a Micromaster in Statistics and Data Science. Here in my lab, very few ...
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### How to show that method X is more reliable than method Y?

I compute a statistic s using two methods, X and Y. In order to measure the reliability of X and Y, I found split half reliability measures (alpha) using a bootstraping technique. So, for each of ...
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### How to do a statistical test for numeric data that is discretised and broken down by groups

Background I have a situation where I have data on bank balances available with various respondents, and a flag for whether they completed a desired action (i.e., whether they purchased a loan or not)....
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### Using two sensors insteaf of one. Statistically meaningful?

We are using resp. manufacturing a certain device which measures, among others, the humidity of liquids. I got asked by a colleague if it makes sense to use two sensors instead of one (which a ...
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### Is there a point where null hypothesis testing is superflous?

Say you're writing a paper and you have the following data Each bar represents an average over a 120 values. I want to determine if the left five and right five sets of data are significantly ...
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### Can you compute a p-value from data with measurement uncertainty [closed]

I have some arbitrary machine learning function that produces both estimates of the target variable ($\hat{y}$) and the variance of $\hat{y}$. I need to compute the p-value if the mean of the ...
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### Is there a way to automatically add significance lines and values to a graph in graphpad prism?

As per the title, I know one can simple draw the lines and add the significance values or asterisks via text boxes but is there a way to do this automatically, say if you have a very big graph with ...
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### What would be the right statistical test and why am I getting different results using Z-test and confidence intervals?

I am trying to determine whether the observed differences in the proportions for two samples are significantly different. 0-hypothesis: The proportions are the same for both samples Alternative ...
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### What is the best way to compare an actual value from an expected value on a linear model? [closed]

I'm comparing the cost of dialysis in each country. The x axis is health expenditure per capita. The y axis is cost of dialysis per patient. As you will see, this incredibly produces a near liner ...
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### power of paired Kolmogorow-Smirnov test

Is the following conclusion correct? Assume I have two data samples, with $n$ and $m$ the sizes of first and second samples respectively. Next, I perform Kolmogorov-Smirnov test with some significance ...
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### SEM: Difference between standardized and non-standardized p-values?

I'm currently working on regressions of one latent factor on another latent factor with lavaan'`. More specifically, I want to examine if depression predicts procrastination behavior. However, I did ...
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### Hypothesis testing : Constant mean over time for two conditions within an experiment

What is an approach to testing/showing that within a particular period of time, there is no change in values. So, I have my response variable measured over 30 seconds, in two conditions. I want to ...
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### How should I interpret a non-significant model effect but significant parameter estimate?

I am running a negative binomial analysis with 2 main effects and 1 interaction. For the variable called "NR", the model effects table shows a non-significant value, but then in the ...
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### Fisher's exact test with more than 2x2 in R or python?

So I have the following in R: ...
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### This function can get p-value from which statistics?

I know that I can get p-value from z-statistic (called zval here) using following function (Python): pval = 2*(scipy.stats.norm.sf(abs(zval))) or with: ...
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### How does the Bonferroni correction benefit from independent tests?

In section 2 of this PDF, it is stated that the Bonferroni correction "benefits" from the tests being independent, and that if tests are not independent, the Bonferroni correction could be ...
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### Finding the right significance test and reporting the results [closed]

I am trying to compare the number of responses given to a psych test with an automatic method (no subjects involved) against the number of responses provided in a dataset that aggregates responses ...
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### Testing the sum of coefficients in regression analysis in R [duplicate]

Hi StackExchange community, I would like to ask how to perform a statistic test on the sum of coefficients in regression analysis in R, possibly using a Wald test. As per my data, I have the ...
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### Is it justified to include non-significant predictors in a model if it decreases the fit criterion (AIC)?

During analysis of a high dimensional dataset (92 cases, 400+ variables) with the goal of statistical inference, I first used a bootstrapped LASSO (bolasso) to select predictors, and then did an OLS/...
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### Chi-squared test for continuous variables (averages)

I'm looking for a suitable statistical test for my situation. The best way I can think of describe it is a Chi-Squared test for continuous data. Please tell me otherwise. Here is a made up scenario: ...
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### Comparison of values by group with covariance

I have 3 groups of different sample sizes with covariance I need to include. I wish to evaluate the value dependence of the groups compared to group 1 (group 2, group 3 values compared to group 1). I ...
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### Correlation between sampled percentages?

I have two statistics from a range of districts obtained by sampling from the total district population e.g. number of doctors per district and the gender of these doctors. Now I want to see whether ...
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### How do you determine the significance of individual deviations in categories?

I have observations from human observers that were intended to place subjects into one of four categories (A-D). In fact, there are 100 subjects in each category. So in an ideal world there should be &...
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### Sample size calculation resulting in too high of a sample

I am trying to perform a power analysis to determine what sample size to use for an experiment after performing a pilot study. However, the sample sizes are showing values that are way too high and ...
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### Techniques for finding UMVUEs

I'm learning about the different techniques available to find the UMVUE such as Rao-Blackwell and Lehmann-Scheffé theorems. My question is how to know when is better to use one method from the other ...
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### Total effect of main variable and it's interaction with dummy

I am going to estimate the following model: y=constant+b1(X)+b2(X)(Dummy) We have daily data from 1990 to 2000. Dummy variable is equal to one for the daily data of year 2000, else zero. b1 is the ...
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### What to choose for null hypothesis and alternate hypothesis? [duplicate]

In this article which explains types of t-tests for “Independent Two-Sample t-test” example: We can confirm that the t-statistic is again less than the t-critical value so we fail to reject the null ...
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### When testing a hypothesis, should I keep an insignificant lag in ARMA-GARCH model?

I am trying to estimate ARMA-GARCH model for my stock returns time series. I have estimated ARMA model for my series, and found that there exists ARCH, so added GARCH(1,1) term. However I now find ...
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### Finding the p value for binary data

I have made an experiment with binary outcomes, and I struggle with calculating a p value to decide if it is significantly different than the control group. There were two sets of identical cells: one ...
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### Mann-Whitney test for a large sample

I'm not a statistician, so pardon me for being naive on this subject. I'm trying to understand if there's any statistically significant difference in the medians of 2 groups. Here are some of the ...
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### Probability of a sample mean higher than population mean

I have solved this question but I am not sure if what I did is correct: It is found that the population mean and standard deviation for the paper are 45.292 and 18.761 respectively. Find the ...
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### Is it correct to evaluate differences of a binary variable between different places with a GLMM?

I am analyzing differences of a binary variable (presence / absence) between 3 wetlands with different pollution using a Generalized Linear Mixed-Effects Models with package lme of software R. My ...
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### Grouping factors by statistical significance in R

I am trying to figure out the best way to group my data into factors to use for creating an MDS plot. I have annual discharge data that I would like to break into "high", "medium" ...
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### Model averaging: predictor significance vs importance

What is the correct way to report the results of model averaging? I’m using MuMin in R, results include a p-value. It’s also possible to get the importance of each predictor. Example results below. ...
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### Use sum of p-values from significance tests to determine best permutation of table columns

I have a table in which there are columns which are entirely filled with numbers. Given another table, I want to figure out which permutation of the other table's columns produces an arrangement most ...
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### How to compare two time-series datasets?

I am trying to compare the financial performance of green bonds and conventional bonds by looking at their historical bond yields, bond prices etc. individually over a certain period of one year. I ...
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### How to test if one value is significantly different from two others?

I'm analysing classroom interaction data. I'm using a simple quantitative index counting the number of interactions of a certain kind. I want to know if it significantly changed between years 1 and 2, ...
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### Statistical test for difference in multiple proportions between 2 groups [closed]

I have two groups of respondents A and B. I would like to know if the overall difference in participation proportion across multiple events (event 1 to 50) between the two groups A and B is ...
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### Distribution from $\lim_{T\to\infty}\int_{-T}^{T}\phi(t) ~dt = 2.$

Let $X$ denote a real-valued random variable with distribution function $F$ and characteristic function $\phi$. Suppose that $\phi$ satisfies the following condition: \lim_{T\to\infty}\int_{-T}^{T}\...
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### Significance Test for the Delta of Deltas

I'm running an analysis on a dataset that captures the test-scores of students before and after they took a class (control group). I also have the same data on an experimental group, test-scores of ...
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### How to compare gender proportions in a population?

I want to test if more women are graduating from high school than men, the last ten years. I want to use percentages, not raw data. (2007-2017 percentages of women who graduated from high schools ...