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14 views

Reporting Fixed Effects as (partial) correlations?

I'm doing a linear mixed effects analysis in which I'm really only interested in one of the fixed effects. I have several other fixed effects and a random intercept term, but none of them are ...
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0answers
18 views

Strange: Partial Correlation changed correlations values to be negative?

I am trying to investigate the correlation values. A big problem happens. The method I used is in corpcor package in R. I have a column as missing data. I firstly calculate the correlation matrix. ...
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0answers
11 views

Two-predictor regression vs partial correlation

Say I want to see whether two variables y and x1 are linearly related, while controlling for the effect of an x2 "nuisace" variable. What is the difference between (a) regressing y over x1 and x2 and ...
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0answers
24 views

Meta-analysis with known confounder

I’m performing a meta-analysis in which the main outcome of interest is a correlation coefficient between two variables, $X$ (a psychological measure) and $Y$ (a biomarker). $Y$ is known to be ...
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1answer
39 views

Partial correlation - scales?

Is there any way to conduct a partial correlation analysis if the DV is dichotomous?
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0answers
89 views

How do I test the difference between two dependent correlation coefficients whilst controlling for other variables?

How do I test the difference between r(X,Y) and r(X,Z) [Williams Test?] whilst controlling for demographic variables that were measured in addition to X and Y and Z [Partial Correlation]? Thanks, ...
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0answers
32 views

z-test in paper false? can Williams Hotelling test be used instead?

I am looking at the statistics of this paper: http://emotional.intelligence.uma.es/documentos/6-Extremera2011Emotional.pdf I am wondering how you can use the z-test to compare the two correlation ...
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0answers
103 views

Comparing 2D heat maps of observed data to 2D model predictions

From "How to ask a statistics question": PROBLEM you are trying to solve: Given two-dimensional heat maps of responses (DV), choose the 2D model (also a heat map, but can have different ranges of ...
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1answer
261 views

Sample ACF and PACF of a random walk

Suppose $X_n$are iid $N(0,1)$ random variables. Define $S_n := \sum_{i=1}^n X_n$. Then $S_n$ is a random walk. Since $Var(S_n) = n$ and $Cov(S_n, S_m) = \min(n,m)$, $S_n$ is not stationary in the ...
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2answers
72 views

Basic information about partial correlation

I'm quite new to this topic, so this is probably very basic for most of you: I want to analyse the relationship of multiple variables via partial correlation as an alternative for a regression ...
3
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2answers
244 views

Which one of these looks stationary?

Step 1. To answer "Final Question" ( linked: "THE FINAL QUESTION : Order of differencing, to achieve stationary and interpretation of arima() , acf, pacf?") Expecting to find correct order of ...
6
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1answer
2k views

Multiple regression or partial correlation?

I don't even know if this question makes sense, but what is the difference between multiple regression and partial correlation (apart from the obvious differences between correlation and regression, ...
2
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0answers
58 views

How to check if two variables are dependent given a third variable?

In R, I have a dataset of many variables and based on correlation matrix I see that some of the variable are correlate with the others. For simplicity, let's assume ...
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2answers
165 views

Generating random numbers based on partial correlation data

I need to generate random numbers based on already existing partial correlation data (not correlation or covariance data). Specifically, a 168*12 matrix based on a 12*12 partial correlation matrix. ...
0
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1answer
589 views

Partial correlation plot, split by groups SPSS

Is it possible to illustrate partial correlation scatter plots for 2 subgroups on the same graph? e.g. I want to make scatter plots of data controlled for age, differentiated by males or females. ...
3
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1answer
728 views

SARIMA estimation

I am trying to manually estimate the non-seasonal components of an SARIMA (p,d,q)x(P,D,Q)[s]. I thought the estimation is going the same way like in ARIMA, but the output says somehow something ...
2
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1answer
115 views

ACF and PACF of AR process with non-zero mean

Calculating the acf and pacf of an AR process with zero mean is straightforward, but does anyone knows how to proceed when the mean is not zero? Of course my intention is to calculate the theoretical ...
2
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1answer
244 views

Meaning of partial correlation

From Wikipedia Formally, the partial correlation between $X$ and $Y$ given a set of $n$ controlling variables $Z = \{Z_1, Z_2, …, Z_n\}$, written $ρ_{XY·Z}$, is the correlation between the ...
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2answers
318 views

Why is the semi-partial correlation sometimes called the “part correlation”?

I understand the difference between partial correlation and semi-partial and zero-order correlation. This terminology makes sense to me in that the partial correlation of X and Y partials out the ...
6
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2answers
894 views

Are standardized betas in multiple linear regression partial correlations?

Since standardized betas are correlation coefficients in bivariate regression, is it the case that standardized betas in multiple regression are partial correlations?
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2answers
1k views

Partial Correlation Interpretation

I was calculating a correlation between two variables (A and B) which revealed these variables are highly correlated. I know that one variable is also highly correlated with another one (C), therefore ...
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1answer
140 views

Partial correlation

I want to create a regression model to predict state crime rate. There are two variables among 10 ( Vi= # of violent crimes per 100,000 population, Vi2 = # of violent crimes per 10,000 population) ...
0
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1answer
339 views

calculate partial autocorrelation [duplicate]

Possible Duplicate: PACF manual calculation I am trying to find a formula for how to calculate partial autocorrelation between variables. We know that aucorrealtion between variables at ...
3
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2answers
423 views

Example where a simple correlation coefficient has a sign opposite to that of the corresponding partial correlation coefficient

Give some examples where a simple correlation coefficient has a sign opposite to that of the corresponding partial correlation coefficient and comment on it. It is a question from an examination ...
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0answers
328 views

Derivation of the formula for partial correlation coefficient of second order

I came across this formula in some online resources. $$r_{12.34} = \frac {r_{12.3} - r_{14.3}r_{24.3}}{ \sqrt {(1- r_{14.3}^2 )(1-r_{24.3}^2 }}$$ I can use this but I wanted a proof of the formula. ...
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0answers
86 views

Find the partial correlation coefficient $r_{1p.2468}.$

Suppose all the simple correlations between $x_i$ and $x_j$ are $r$ for all $i,j=1,2,\dots,p, i\neq j.p>8$. Find the partial correlation coefficient $r_{1p.2468}.$ By definition, ...
3
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1answer
279 views

What is the interpretation of “generalized” partial correlations?

The usual partial correlation between X and Y given the set of variables Z is the Pearson correlation between residuals resulting from the liner regression of X on Z and Y on Z. It can be computed ...
3
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0answers
119 views

Visual depiction of experimental treatments in (Poisson) ANCOVA?

Goal: I want to visually depict the difference between experimental treatments while controlling for a continuous covariate in Poisson regression. In my experiment, I am seeking to explain the number ...
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1answer
7k views

How to deal with high correlation among predictors in multiple regression?

I found a reference in an article that goes like: According to Tabachnick & Fidell (1996) the independent variables with a bivariate correlation more than .70 should not be included in ...
3
votes
1answer
248 views

When is regressing out factors serially, equivalent to a simultaneous model?

I have two factors $a,b \in R^M$ which I wish to regress out of my variables $Y \in R^{M \times N}$. $b$ is a function of the variables $Y$ and is defined as: $b = \frac{1}{N}Y1$ Regressing out the ...
2
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0answers
719 views

Geometric intuition for why an outer product of two vectors makes a correlation matrix? [closed]

I understand that the outer product of two vectors, say representing two detrended time series, can represent a cross-correlation (well covariance) matrix. I also know that the inverse of a ...
1
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0answers
174 views

Some questions about VAR-models, $\Phi$-matrix-coefficients and partial-(auto-)correlations

There is an abundance of literature about VAR-models, which teaches how to test preconditions, specify and estimate VAR-models for stationary and also cointegrated time-series. However, I'm still a ...
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2answers
351 views

How to explain the partial correlation result?

For example, I have three variables: A, B, C. I analysis the partial correlation between A and B while controlling C (expressed as A~B[C]), and the partial correlation between A and C while ...
1
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1answer
242 views

Interpreting Omitted Variables

I do not fully understand how to interpret the difference between two statistical models where they only differ based on whether a certain variable is included on the right hand side. If the results ...
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0answers
133 views

Do path coefficients (beta) for the same condition across model comparisons have to be equal in structural equation modeling?

This is a long-winded question but I'll try to paint the picture. I'm using structural equation modeling using Amos software to study relationships between brain and behaviour. I have three condition ...
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2answers
39k views

How exactly does one “control for other variables”?

Here is the article that motivated this question: Does impatience make us fat? I liked this article, and it nicely demonstrates the concept of “controlling for other variables” (IQ, career, income, ...