Questions tagged [statistical-significance]
Statistical significance is a characteristic of a statistic viewed in light of a null hypothesis and a given significance level. It reflects whether the statistic belongs to the rejection region (is statistically significant) or the acceptance region (is not statistically significant).
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Statistical tests for distributions on constrained intervals
I have a continuous distribution of angular values on the interval of 0 to 90 degrees. This distribution is expected to follow a half-normal distribution with a greater frequency of values toward zero....
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Logistic regression yields very small p-values for any/every explanatory variable in my dataset
I'm investigating whether a federal district court judge's ABA rating (rating given to the judge by the American Bar Association when he/she is nominated) significantly correlates to the rate that his/...
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Regression - Merging separate linear regression models
I'm trying to assess if the following intuition has sense or not. Any help will be appreciated.
Consider two simple linear models obtained in the same experimental framework (for example, measurements ...
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What is the best way to test for a relationship between a binary variable and a continuous variable?
Suppose I have a dataset with a continuous numerical variable $x$ and a binary numerical variable $y$ (with values 0 or 1).
How can I test the null hypothesis that the value of $x$ has no effect on ...
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How to measure the impact of a feature or set of features on the classification performance?
I have a dataset as follows:
mydata:
f1,f2,f3, ..., fn, target
s1 34,56,32,...., 43, 0
s2 37,60,33,...., 54, 1
....
sm 89,86,56,...., 90, 0
I ...
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how to calculate median follow-up time?
I have a hospital based dataset which conatins information on patient details. Right from their visit, drugs, diagnosis, lab tests, and death info etc.
So, now I would like to compute their follow up ...
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Minimum sample size required in paired t-tests and statistic significance
I want to test if new technology machines can make people consume less water in their homes.
I have around 150 of those machines, where they can be divided into 3 types of technologies (A, B, C), i.e. ...
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Uncovering the make up of the intercept in a generalized linear mixed model
I could use some help Finding the make up of the intercept in a generalized linear mixed model.
FYI, I use a 2013 Macbook Pro with a 2.4 GHz dual-core intel chip, 8 GB of ram, macOS big sur 11.2.2, ...
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How do I find a minimum sample size for the proportion test / T test?
What I want to figure out is how to find a minimum sample size for comparing a sample to the whole population when the ratio of the sample to the population is less than 5-10% (e.g. 30 to 1000).
The ...
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In a replication study, if the sample size decreases does the mean decrease as well?
At the start of the Tversky's 'Belief in the law of small numbers' is a hypothetical replication study that motivates the essay. A full description is provided by this question. But in essence, a two-...
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Difference between Chi^2, Chi^2/dof and R^2
I have radioactive decay experiment (so the model is y = Ae^(-kt)) results and am (slowly) teaching myself mathematica to plot this. I want to output some measure for the goodness of fit, but am ...
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Statistically validate clustering results
I have performed consensus clustering on a data set (N=2500), which resulted in a best value of k=3. The data set is from the medical domain, and the features ...
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A statistical test to determine if the change over the years is statistically significant?
Somehow my brain resists to understand statictics, sadly.
I have been searching a proper statistical test to analyse my data.
I would like to test if the trend I see in my data is statistically ...
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Establishing a P-Value-type significance measure when data is in discrete categories
Imagine you have 2 ethnic groups on the planet Zorblax. Let us call them the A's and the B's.
Stealing on Zorblax can have 3 different penalties:
A fine
A jail term
Death penalty
In a certain year, ...
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T-test vs. Wilcoxon Rank Sum Test vs. Bayes
I am looking at a case where i have traffic to a page with say 10,000 visitors. About 2% of those visitors buy a product between $20-200. I want to test if a site redesign will increase my average ...
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Significance of subcategories
My data includes a total sum of around 30 different subcategories. If I want to find if the subtotal of these subcategories is significantly different from previous quarters I can run a chi square ...
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Margin of Error in a NPS result with promoters only
This is a follow-up to the response provided by @whuber on the question How can I calculate margin of error in a NPS (Net Promoter Score) result?
@whuber pointed out that there are more sophisticated ...
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F-test: How to use type I error to compute type II error?
Here is the conclusion from the reference
https://www.real-statistics.com/chi-square-and-f-distributions/power-of-two-sample-variance-testing/
Let $s_1^2$ and $s_2^2$ represent the variances of two ...
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Moderation: Interaction is not significant but sum of coefficients is significant
I have a simple model:
$Y=\beta_0+\beta_1 X + \beta_2 Y + \beta_3 XY+\epsilon$, where Y is a dummy variable.
I found that $\beta_1=-0.17, \beta_3=0.04$. While $\beta_1$ is statistically significant, $\...
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Determining correlation between discrete data
I have two variables
The number of likes that a comment has received.
Total AFINN score calculated from a comment.
Now the AFINN algorithm assigns an integer based on the sentiment of each word (...
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A priori publication of statistical analysis plan (SAP) for clinical trials
This is somewhat of a regulatory question, rather than statistical question. But I assume that the readership of this community will be the most knowledgeable on this matter.
Question:
Is there any ...
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Guideline one using which statistical test?
Are there any guide lines on determining which test to use?
For example, given 100 subjects with both Exam A and Exam B, and some student observations for those exams, i want to compare which exam is ...
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Looking for scientific validation for a heuristic model
The problem: infer the nationality of a person from a limited number of features (name, email, ...).
I do not have enough "ground truth" to use ML techniques, I'd like to try what for a ...
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Changes in significance between Poisson & quasipoisson glm
I am fairly new to GLMs, and am currently practising and testing with an insurance dataset, after many tries, I am modeling the frequency (counting model of the number of claims) and I have several ...
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Use of Chi-Square test of independence / Fisher Exact Test?
One of my research hypotheses is that individuals from Southeast Asia who are ethnically Chinese are more likely to experience racially motivated hate crimes than their counterparts from other ethnic ...
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How to perform a statistical significance test between 2 groups of binary data?
I have a binary column where 0 means fail and 1 means success. This column have been grouped by a second column called events. Here's a data sample before grouping:
...
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Box and whisker plot looks significant but paper says it is not?
I am reading this paper "Long-term vitamin D treatment decreases human uterine leiomyoma size in a xenograft animal model" and one of their plots looks strange to me.
According to the paper,...
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Panel Match: ATT estimate level of significance
I am a novice user in R. I'm working with Version 1.3.1093 and Windows .
I'm working on a Panel Data Set for all activist interventions by hedge funds in Europe for the period 2005 - 2019(time ...
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A very big JB value in Jarque-Bera test [duplicate]
I have run the JB test for my data using two different commands. I am quite clueless about what conclusion I can make from the second picture which shows results of 0. This tells me that there is no ...
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Chi-square, p-value and political elections
I am looking at which category is mostly associated with people who voted.
A sample of results from my dataset is as follows
...
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Rewriting coefficients of a regression
We are interested in the variable $\alpha_1$, in the equation
$
y_{iv1}=\alpha_0 + \alpha_1group_v+x_ia_x+ \gamma y_{iv0} + \epsilon_{iv1}
$
Where $y_{iv1}$ is a dummy variable, and $x_ia_x$ denotes ...
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Does central limit theorem help in making inference only about the population mean and not other parameters?
As per the weak law of large numbers, if your sample size is large, your mean of the sample is likely to be closer to the population mean than in a smaller sample. Additionally the CLT tells us the ...
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Asymptotic variance of a sample skewness in Bai and Ng (2005)
I am reading a paper from Bai and NG (2005) and trying to code asymptotic variance of sample skewness from Theorem 1:
Suppose $X_t$ is stationary up to sixth order. Then
$$\sqrt T (\hat \tau - \tau) \...
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Is sample skewness statistically significant?
I've been searching for a research that would examine statistical significance of a sample skewness between two financial time series of returns. Unfortunately, I was not able to find any good or ...
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Are significant small effects (standardized coefficients) valid on extremely large samples?
I am testing a path model on a sample of 12.000 subjects. All the path coefficients have extremely low values (e.g. 0.003, 0.012) yet they prove significant.
How do I know I am detecting a ...
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Event study: test for cumulative abnormal returns
I am performing an event study, across different firms, using the market model theory.
$$\
{R_{it}=α_i+β_{i}R_{mt}+ε_{it}}$$
With Abnormal Returns (AR):`
$$AR_{it}=R_{it}−α_{i}−β_{i}R_{m
t}$$
How can ...
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Conflict between OR confidence interval and p-value
I'm currently reading this study about the adherence to health checkups in Austria. Table 2 displays some Odds Ratios for attending health checkups between groups of different educational statuses. I ...
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Computing statistical Significance of Rank Order Question
In my questionnaire, I have a rank order question concerning three different videos. Each respondent must rank each of the videos either on position 1, 2 or 3. All respondents are in the same group (...
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Which one-sample statistical test for ordinal variables?
I have one group of <25 subjects and multiple evaluation scores:
New images of every patients has been rated by a radiologist compared to old images (1 to 5 with 1 Markedly worse, 3 similar and 5 ...
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How to compare predicted Y against a constant at different levels of a continuous X
I have a simple linear regression with a continuous $X$ (Likert scale, range 1 to 7) and a continuous $Y$ (people's prediction about an event, range 0 to 100). I want to see if the predicted $Y$ at ...
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Statistical test that compare observed events with expeected
Could anyone enlighten me on what will be the appropriate statistics to test whether a series of events is significantly different from the expected or not.
For example, there is a pool of infinitive ...
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How to test difference between two subgroups in one sample - how to decide about normality in the subgroups?
I distributed one questionnaire to a group of 191 respondents (Questions on Likert scale). I split the sample into men a women. I would like to see, if the difference between them is significatn (if ...
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Contrast post-hoc test on non-significant factor levels
Is it meaningful to interpret the contrast result from a post-hoc test on factor levels that have non-significant coefficients in the fitted mixed model regression?
I'm using a contrast test using <...
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Whitney Mann U test vs Kolmogorov Smirnov for a highly skewed continuous variable
I would like to compare task time to completion distributions (measured in minutes) across two groups. The distributions are highly skewed (the means are 300 to 400 times larger than the medians) and ...
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How to test the equality of two proportions with multiple samplings?
I am searching for a statistical test to compare two proportions of responsive cells.
I know that Khi2, z-test and Fisher’s exact test allow this kind of comparison but the issue I have is that I have ...
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Testing if a day of data is an outlier
I have a time series which exhibits a relatively similar behavior from one day to another. I want to know if a specific day of the time series is an outlier in the sense that it significantly differs ...
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Statistical testing of proportions to include multiple experiments
I am struggling with understanding what is the correct statistical method to use to determine the statistical difference in proportions for multiple experiments. Let me explain my scenario.
I have run ...
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Statistically significant difference in R^2 between two linear regression models
We are interested in if the difference in R^2 between two linear regression models is statistically significant (the metric of model performance doesn't necessarily have to be R^2 but that is what we ...
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Does the problem of multiple testing also apply to the testing of assumptions?
When dealing with statistical tests, sometimes we can run into cases where many assumptions would apply and consequently would need to be tested. In complex models, testing many assumptions at 5% may ...
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test if 5% difference is significant
I have a dataset that contains 20000 chess matches. According to these matches, white won 50% of the games while black won 45%. I want to test if this 5% difference is significant. How can I do that? ...
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