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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Why would standardized betas be high (e.g. .66) but non-significant in moderated regression?

Running a moderated regression using PROCESS macro in SPSS (issue replicated by running the same moderation using mean-centered variables in SPSS linear regression command box), I am finding that the ...
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10 views

Artificial Data Generation based on Data Distribution

My data looks something this (for example): Salary | Age | Zip | Class 60000 | 35 | 5 | Yes 50000 | 52 | 4 | No 10000 | 25 | 3 | Yes 70000 | ...
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25 views

Classifying groups using statistical significance

I am really struggling to get my head around some sample questions of my quant class. The exam is looming and I cant grasp what must be a basic concept. Sample A service provider has identified ...
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13 views

Indicator regressions: standard errors

Hi I am estimating a regression of Y on X where both Y and X are indicator variables, that is, they take values 1 or 0. The model is $Y=\beta*X+\epsilon$ (without constant). I use OLS to estimate the ...
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14 views

Estimating treatment effects on unequal groups

The setup is quasi-experimental: treatment and control groups, chosen ahead of time, are given a pre-test and a post-test. They are close to equal in size, and while membership was selected based on ...
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7 views

ANCOVA model with non-significant variables performs better?

I'm running an ANCOVA test with 2 dichotomus and 1 ordinal variable as fixed factors and 2 continuous variables as covariates. I was advised to remove any non significant factors because with them ...
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11 views

Interpretation of non-significant parameters in significant Cox-model as prognostic factors

I want to analyze predictive factors for patient survival after surgery. I have variables that are based on investigations at the time of the surgery, known predictive factors (age, KPS) and data on ...
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1answer
23 views

Statistical test for classification models

I have 3 models from which, for each model, I train a classifier and then evaluate it, currently using stratified 10-fold cross validation and then take the mean accuracy ratio of these from each ...
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17 views

What to display for differences of medians of discrete variables?

I am using the Mann-Withney U test to compare two samples of count data. In several situations, I find that there is a significant difference between the populations, but when I estimate the CI for ...
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1answer
17 views

Is it common practice to correct for multiple comparisons with multiple ANOVAs?

I gave three groups of participants (say groups A, B, and C) different treatments, then gave all groups the same questionnaire. The questionnaire has ~50 questions. I then run ANOVA on each of the ...
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2answers
87 views

Aside from Durbin-Watson, what hypothesis tests can produce inconclusive results?

The Durbin-Watson test statistic can lie in an inconclusive region, where it is not possible either to reject or fail to reject the null hypothesis (in this case, of zero autocorrelation). What other ...
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1answer
19 views

Confidence intervals for percentage share of multiple response

If I have a sample of 100, who give responses to a set of multiple response variables, say for example, the brands they have purchased in the last 12 months. How can I calculate the confidence ...
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2answers
48 views

Comparing frequencies

I'm trying to find the right test to use to compare 3 frequencies. Basically, in my research, 3 separate user interface prototypes were given to the same sample (10 people) and particular tasks needed ...
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21 views

Position Based statistics in DNA sequence

Let's say you have a DNA sequence with 21 positions, each of which can have one of four nucleotides (A,C,G,T). For example, If I see lot of C's and G's (called 'GC content') at 19th position in all ...
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2answers
25 views

Help find a statistical test for proportion of a binary outcome with repeated measures

Here is an illustration of my problem: I have two stimuli (A and B) given to a number of subjects. Each subject is sequentially subjected to both stimuli 5 times (AAAAABBBBB or BBBBBAAAAA, but not ...
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1answer
24 views

Bonferroni Correction for Post Hoc Analysis in ANOVA & Regression

As we know, if we are doing many tests or multiple comparison, we don't use the same $\alpha$ value and use some $\alpha$ correction methods like Bonferroni. This is done because when we do multiple ...
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25 views

Likelihood of burning for a type of vegetation - which test to use?

I have six categories of vegetation, their total surface and the percentage of surface that has burned. I want to say eg. "coniferous vegetation burns more often on a statistically significant level". ...
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33 views

Statistical Significance?

I'm wondering if there is some sort of statistical significance test that would suit my data, or whether I have to depend solely on descriptive statistics. Here's what I've got: Thirty six students ...
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21 views

How to interpret statistical significance [closed]

I am having trouble differentiating statistical significance from the below multiple choice questions. What would be the correct answer for both questions? A result with a significance value of ...
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1answer
42 views

Proving similarity between two rankings

We are seeking a comparison of two different rankings of the same 3 systems Background: We have conducted a test of 3 different systems. Participants experienced a system and rated it on a 7-point ...
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7 views

Interpreting a significant interaction with only 1 out of 3 dummy variables (arising from same categorical variable)?

I'm running logistic regression analyses (paired observations - we cluster on ID code (=xtlogit in STATA)) with: dependent variable: trust (0/1). independent variable: - eye pictures ...
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34 views

Efficient statistical test to compare two multivariate distributions

I am looking for a test to assert the "equality" of two multivariate discrete distributions, $\mathbf{A}=\{A_1,\dots,A_k\}$ and $\mathbf{B}=\{B_1,\dots,B_k\}$ for which I do observe two samples ...
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30 views

Two dimensional Kolmogorov-Smirnov test

For a one dimensional Kolmogorov-Smirnov test there is a theoretical result, one can compare his or her test results directly by theoretical one, which is infinite sum (notice this formula is for big ...
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4 views

Test statistics for MAPE

I am working with longitudinal panel data where I use variables of the first panel wave as training data in a regression to predict the consecutive waves. To compare different prediction approaches I ...
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2answers
38 views

Appropriate visualization for the Wilcoxon signed rank test

I have question regarding the Wilcoxon test and if the results can be represented visually. I had 10 participants in my experiment where by I asked participants to read sentences and then they ...
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18 views

Intuition behind Whites reality check

Assume you mined some strategy following a simple rule based approach with positive performance measures over the last 30 years from a giant parameter space. Now you want to find out how likely it is ...
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15 views

Chi-square and subsequent comparisons

I have the following dataset and would like to find out firstly if I'm using the correct tests. The data are hospital admissions data for cause X and admissions data for all admissions. If an ...
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1answer
35 views

Is my Interpretation of this statistical distribution correct? [closed]

The torque of shld flx action was between 8Nm to 10NM for 10% of the time Is my interpretation correct? If so how do I determine torque for one of the 19 activities?
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21 views

How would I calculate the t-statistic for this data and then determine if it's significant?

Say we want to test the hypothesis that a control group of cancer patients would report higher mean pain ratings than an experimental group receiving special massage treatments. Group 1: Mean = 78.1 ...
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1answer
63 views

How to analyze if only N and means are available?

I have data on following experiment: Sample taken from each of 5 normals and 5 patients All normal samples are pooled and mixed together. Similarly all patient samples are also mixed ...
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11 views

Is there a way to determine if commonalities between two sets are significant?

I have two sets of genes that I want to compare, and I'm wondering whether the common members between the two sets are significant. Is there a way to derive a p-value to deem the common set to be ...
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13 views

Find significance level of test given rejection region using order statistic

$\textbf{Question:}$ Given that the random variable $X \sim \mbox{geom}(p)$ and the test $\begin{cases} H_0: p =\frac{1}{2} \\ H_1: p > \frac{1}{2} \end{cases}$, find the significance level ...
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1answer
24 views

Calculate Significance between samples with skewed data

Background: I have a sample that is very left skewed. The mean of this sample is 4.01 (min = 1, max = 5). I would like to know whether or not a subset of this sample is significantly different than ...
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1answer
83 views

When is Variance Statistically Significant?

This may seem like a rudimentary question relative to other posts, but how do I determine whether the variance is statistically significant? For example, let's say I have a population of 10000. I ...
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16 views

Losing power by doing repeated measure instead of standard anova

I have an experiment with one within subjects factor. It has 3 levels: sleep deprived (24 hours), sleep deprived (12 hours), not sleep deprived. Over the course of 6 weeks we run a counterbalanced ...
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10 views

Manufacturing Process Validation - Sample size calculation

I am new to manufacturing process. Can someone help me to determine the sample size required to perform Manufacturing Process Validation? I know nothing about six sigma, so simple answers are highly ...
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1answer
45 views

Is it possible to calculate Q1, Median, Q3, StDev from already aggregated data?

We have data that will get aggregated per hour into the following values Q1 Median Mean Q3 Standard Deviation Max Min Count of Values So the data will look more or like this in the end. ...
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0answers
10 views

Results from petest do not match documentation

I am trying to use the petest function in R (http://www.inside-r.org/packages/cran/lmtest/docs/petest) to decide between a log or a linear model. The documentation, and the referred textbook, both ...
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39 views

How to show whether a hypothesis is true or not

I have the following hypothesis: "The higher the number of translation-stable words between a pair of countries, the higher the correlation between the happiness scores of their words". note: ...
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2answers
70 views

Example of interpretation of logistic regression

I was looking at a paper by Pell JS 2009, regarding smoking and survival following acute coronary syndrome. Part of the analysis carried out in the paper was a logistic regression with results as ...
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40 views

threshold based on mean and standard deviation

I have a time series of 70000 data points. I want to separate samples of this time series which have very large values as compared to the time series. How can i threshold sample to separate. What i ...
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1answer
34 views

Regression coefficient model

Suppose a researcher studying the incidence of cardiovascular disease estimates a regression model by including information on each person’s cholesterol level (as an independent explanatory variable). ...
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14 views

How to perform F-test significance testing in Matlab?

I have two quantities in Matlab say T1 (1x44100 array) and T2 (1x44100 array). I have calculated their ratio ...
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11 views

How to compute SNR output in independent component analysis

I work in speech denoising and I use independent component analysis (ICA) to separate the noise from the speech signal. I compute $\text{SNR}_\text{input} =10 \text{log}_{10}\left( ...
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2answers
47 views

F-distribution of data in Matlab

I have F = 1x44100 vector in Matlab. Based on how this was calculated, we have predicted that this fits the F-distribution with 16 degrees of freedom for both numerator and denominator. I am really ...
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1answer
26 views

Testing the sum of GARCH(1,1) parameters

How can I test that the sum of the $\alpha_1$ and $\beta_1$ parameters in a GARCH(1,1) model is significantly different from 1?
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1answer
42 views

Statistical significance for many instances of Kendall tau correlation

I am working on a dataset, which contains multiple instances of ranking vectors, done by two annotators. In particular, I have about 20,000 data samples. Each sample contains a ranking of 4-5 items ...
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0answers
18 views

Are two sets of multiple choice survey responses different?

I have survey data with 2 distinct types of respondents: tall people and short people. They've answered a series of questions about their preference for certain foods. I'm trying to determine what ...
3
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1answer
48 views

Significance of individual coefficients vs Significance of both

This was a question I read from google quantitative analyst interview on glassdoor: If each of the two coefficient estimates in a regression model is statistically significant, do you expect the test ...
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0answers
19 views

Odds ratio and interpretation when 95% CI overlaps 1 but is marginally statistically significant [duplicate]

I'm working on an a logistic regression analysis and using a alpha value of 0.10. I found one of my variables to be marginally significant (P = 0.098) with the odds ratio of 0.963 (0.920 - 1.007). Is ...