# 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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19 views

### Why do some rows in gtsummary output show OR=1 and CI containing 1 but have significant p-values?

0 I am using gtsummary to create a table that merges univariate and multivariate regression results. Here's the code I'm using: ...
21 views

### How do I compare the success rates of two groups of two different sample sizes?

I have two drugs. Drug A and Drug B... I did a test where I gave one group Drug A and another group Drug B. For the group I have Drug A, I saw a 20% cure rate. For the group I gave Drug B, I saw a 17%...
3 views

### What is the most common Nonparametric Global Test of Difference for Repeated Measure?

The experiment goes like, there are two different machines, Machine_A and Machine_B and a Technician. The machines have the same purpose which is for measuring a continuous quantity (be it weight, ...
229 views

### Calculating statistical significance of gender discrimination in a CS class

Can someone help review my analysis below and provide any feedback? Problem In a Computer Science class of 30 people comprising of 6 females, is there statistical significance of gender discrimination ...
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### Comparing pre and post treatment data - best statistical test?

I am analysing a range of clinical outcomes for a drug treatment and need to compare the values pre and post treatment - I’m using excel to do this and have found that for most of my outcomes the data ...
31 views

### Tests that Quantify Deviation from Null Hypotheses

I have been delving into non-parametric tests recently, and I've come to realize that most of these tests offer only a partial perspective. For example, lets say the underlying distribution is $\theta$...
11 views

### Contrasting Results in Regression Models: Flow vs Stock Variables in Policy Impact Analysis

I am conducting a study to analyze the impact of a specific policy on the number of businesses in each region. The policy was implemented in a staggered manner across different regions, and I'm ...
92 views

### E-commerce - Does higher delivery time lead to lower sales?

Question I have a practical problem and am seeking guidance on how to use statistical methods to solve it. I have an online store. The products in the online store have varying availability: 24 hours ...
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### What is the best test to use?

I am working on a project in my R introductory course but I really dont know what statistical test to use. I got my data from the Malaria Atlas Project. I want to know if the the Use of insecticide ...
17 views

### Best test for comparison of temporal counts

I have a data set of 182 concurrent count observations using two different methods and I was wondering what would be the best test to evaluate how closely related they are to each other. My data set ...
11 views

### Comparing representation of female subjects from past and current consensus statements

I am comparing the number of female subjects represented in studies for a consensus statement from 5 years ago, to a current statement. I have counts of female representation for each statement broken ...
21 views

### How can I interpret a P value of 3.1E-08? [duplicate]

I used T test paired two samples for mean for comparing 2 groups of data (pre and post in the same population) and got this results. What does it mean. I am trying to figure out if the 2 data samples ...
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### De Longs test on ROC curves?

I have two different ROC curves for Model A and B. I wanted to calculate the DeLongs test to identify the statisical significance of the difference between the model. model_A_tpr = [0, 0.2, 0.4, 0.6, ...
30 views

### Significance testing between two set of SNPs

After performing GWAS, I calculated the percentage of phenotypic variance (SNP-based heritability) for top SNPs and random SNPs using GREML (GCTA). The variance of random SNPs was calculated for 3 ...
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### How can mahalanobis and chi2-test be used to determine of an observation is acceptable?

Assume that you have a model $$\dot x = Ax + Bu$$ $$y = Cx$$ And this model is SISO. Single input and single output. You got the mission to determine of an observation is acceptable for the kalman ...
21 views

### Practical use of a confidence interval [duplicate]

I wrapped up my undergraduate statistics degree recently and am about to start a stats heavy role as my first job. I've been brushing up on my frequentist knowledge and I'm currently trying to find a ...
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### Probability of both M and N consecutive head runs in K independent tails terminated coin toss runs

Let's say I repeatedly toss a coin each day, until I get tails which terminates each run. I do that 1999 times (1999 runs). I count how many heads I got each run. 0, 1, 0, 3, 0, 2, 1, 5, 0 etc. What ...
52 views

### What is the operational definition of "practical significance"? [duplicate]

Statistical significance-testing implies whether a sample-statistic matches with population estimate of effect-size.(mean,r or d etc.).It is based on sampling theory. The interpretation of the "...
7 views

### Metric for run-to-run consistency of time series data

If I run $n$ samples of a physical experiment, I expect to see roughly similar time vs. position plots but with slight variations run-to-run. What are good statistical metrics to quantify the ...
1 vote
19 views

### calculating a statistically significant difference in means between groups

A large number of subjects repeatedly pass or fail a test. The test frequency is irregular and randomized per user. Organize this data set in groups by the average test frequency being once per week (...
1 vote
15 views

### How to do a pairwise test of each regression model coefficient over groups?

Given a regression model $F(X) = y$, where $F(X) = \beta_0 + \beta_1:groupX + ...$ I want to test a null hypothesis that there is no difference in the coefficients between groups for each coefficient ...
1 vote
52 views

### Appropriate statistical test with pre\post experiment

This might be very simple so excuse me in advance. I'm trying to test if the difference between five test scores is statistically significant in a pre\post experiment with three different times, as ...
45 views

### Variance of sampling distribution

$\operatorname{Var}(\bar X)=\sigma^2/n$ is the formula of variance. I want to check my understanding of this concept. Suppose I want to compute the mean household income of a given city. I collect all ...
1 vote
22 views

### Is a power analysis appropriate when the predictor variable is bounded between 0 and 1?

I am doing a power analysis (PA) to find the minimum sample size to detect a difference between two groups (with acknowledgment of the theoretical problems involving using p-values, etc.). The mean ...
28 views

### Abusing statistics- assessing the power of classification connection by flipping X and Y in a linear model

I am supposed to check the significance of the connection between an arbitary Y variable (nominal\ordinal\binary I cannot know in advance) and an arbitary numeric X variable. This is a classification ...
1k views

### Got some wacky numbers doing a Student's t-test

For context, I am currently enrolled in a Quantitative Analysis course for chemistry at my university. We've been focusing on errors and statistical analysis to determine whether the random error is ...
40 views

### Non-significant predictor variable becomes significant when two control variables are introduced into model

I want to investigate the correlation of $A$ and $B$ on $X$, so i do a multiple linear Regression. On their own $A$ and $B$ are significant predictors of $X$ in a simple linear regression. When i test ...
42 views

### How to Check Linearity Assumption in Logistic Regression with a Large Dataset?

I am working with a very large dataset that essentially covers the entire population of interest. I want to assess the linearity assumption between an independent variable and the log(odds) of the ...
429 views

### How can I interpret it when correlation between two variables is significant, but not in a multiple regression?

I want to investigate the correlation of $N$ and $G$ with $X$. In a correlation matrix, $N$ and $G$ are both positively correlated with $X$. $N$ and $G$ are correlated, too, by the way. In a multiple ...
1 vote
39 views

### Correct statistical test to model user preferences among multiple models

My problem involves comparing the performance of machine learning models to how good each model's recommendation is. The way I'll design the experiment is as follows: I'll send out a form to multiple ...
1 vote
38 views

### How to compare linear regression coefficients with factors in R? [duplicate]

I have 2 continuous variables $(x,y)$ for a dataset $n=186$ that has a strong, positive linear relationship ($m = .46, R^2 = .96, p<.05$). Within this dataset I have 3 different habitat types (B,F,...
20 views

### Which statistical test to apply to calculate if a difference is significant between annotations?

I have the following problem: I have a text which needs to be annotated with named entities. I have two annotators who have annotated the text twice. How can I calculate if the change in the number of ...
1 vote
20 views

### Fixed effects regression for unbalanced panel data (sample size, interaction term, statistical significance)

I have a highly unbalanced panel data set (n= 70 firms, T= 5-3000 observations per firm, N= 15000 observations overall). I specified a fixed effect regression with time and entity fixed effects. I ...
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### Detecting biased coins

EDIT: By detecting I mean to statistically confirm, with a certain confidence, if the coin is actually biased or not, with a particular bias of $p = 0.57$. I'd like to know what is the best way of ...
11 views

### Outliers over multiple time series

I got roughly 400 time-series measurements which are concerned with the sentiment of chat messages from different videos. I want to detect if there are videos which have a higher or lower sentiment ...
32 views

### Statistical Approaches for Interpreting Weekly Changes in a Percentage Metric

Overview Each week we have some number of trials and successes, and we track the percentage of successes each week, this is our metric. Made up example: A loan company - each week we get some ...
1 vote
27 views

### Why is the sample standard deviation used in the z-test?

The assumption of the z-test is that the population standard deviation $\sigma$ is known. With this in mind I tried to manually compute the p-value for a (one-tailed) z-test that the sample mean \$\bar{...
18 views

### Is it possible to use acritical value from the F distribution with a CI of 95% and obtain the z value with a CI of 99% in the same problem?

I am studying this article "Variance sensitive adaptive threshold-based PCA method for fault detection with experimental application (Alkaya,2011)" in order to apply the adaptive threshold ...
1 vote
102 views

### Why do we use the t test statistic?

I am trying to understand the rationale behind the t-test. To explain my question(s), let's assume a simple scenario in which we want to do a one-sided test whether the mean of a sampled random ...
1 vote
23 views

### Effective sample size after applyting butterworth filter

I have a signal s with a total length of N*D in time, which I break into N observations of ...
29 views

### Quantifying fit of a non-linear model

I have developed a non-linear model that utilizes 0-fitting parameters (all my inputs can be/are determined experimentally). As of now I have performed propagation of error and a GSA using Sobol ...
67 views

### Appropriate statistical test to determine if uplift between control group and multiple test groups is significant (pretest/posttest evaluation)

I'm trying to evaluate whether the difference in uplift seen in below table between the test groups and the control group is statistically significant. I'm unsure about the appropriate statistical ...
328 views

### What is meant by practical significance and statistical significance? How do we distinguish these concepts? [duplicate]

I am unable to understand content reported in : Practical vs Statistical significance Statistical significance-testing implies whether a sample-statistic matches with population estimate of effect-...
24 views

### Non-Parametric Test for Regression Significance

I have created a plot of the regression slope of sea surface temperatures (x) and an atmospheric variable (y). Although, I need to test the statistical significance of these trends using a non-...
62 views

### Sample size and minimal clinically important difference

my study is a randomized controlled clinical trial involving 3 groups in parallel. Sample size was calculated based on blood cholesterol endpoint as 20 participants per group. However my problem is to ...
21 views

### Looking for a statistical test that discovers whether a set of values is statistically significant from an established value

I am working with a set of vowel lengths generated by non-native speakers of English and I want to find out whether they are consistent with vowel lengths generated by native speakers of English ...
34 views

### How to interpret PLS-MGA’s results based on the significance of the corresponding group specific path coefficients

As a more general follow-up question to Elisa’s post on “[h]ow to interpret regression coefficients” when carrying out a PLS-structural-equation-modeling multigroup analysis (PLS-MGA), when comparing ...
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### Sargan test results = 1 in system GMM

I am having difficulties understanding my diagnostic test results for my twoways effects two-step model system GMM, which I performed in R. The results of my Sargan test (test for overidentification ...
1 vote