# correlation

1. ### Reporting corrected correlations

Hi All, I need to report a large set of correlations whose p values I have already corrected for multiple comparisons using R. I assume that the correlation coefficient will remain the same, as nothing in the r formula has anything to do with how the p value is calculated. 1) Is that correct...
2. ### Correlation signficance

I would appreciate help in checking whether my attempt to decide whether my correlations are significant is correct – I suspect not, and would welcome a correct set of functions. After computing the correlation of two arrays, for example: JL50: CORREL($QW$5:$QW$46,JL$5:JL$46) = 0.4084, I then...
3. ### Nonparametric alternative to point-biserial correlation coefficient? - Which? t-test or Mann Whitney?

A. I know from the net that for a design with one binary variable and a second variable that is continuous but is NOT normally distributed, I can use BOTH the point-biserial correlation (which is basically the parametric Pearson correlation formula) as well as the Rank Biserial Correlation...
4. ### Negative correlation, but positive effect in multilevel regression

Hello, I am doing a longitudinal multilevel analyses. I am researching the impact of certain restricting abortion policies of US states on the number of abortions. Furthermore I control for the characteristics of these states. One of these characteristics namely poverty rate of a state, has a...
5. ### How to create a Pearson Correlation and others with this data?

Hello everyone.. I am struggling to create a Pearson correlation with this data below: My goal here is very simple, identify correlations between each module and the severity number. (Its related to Defects) I tried Pearson correlation but did not work out well. Can someone give me a hint of...
6. ### Comparing two dependent, non-overlapping correlations

I have two questions regarding the comparison of two correlation coefficients from a single (paired / dependent) sample: Is it legitimate to use a test for comparing independent correlation coefficients instead? My understanding is that the only drawback is that this would compromise power...
7. ### How to interpret relationship between variables when one value has a disproportionate number of samples

Hello all! I am in the beginning of a statistics project in my master's course which will be focusing on regression analysis later on. We have not yet done any regression analysis but have been asked to turn in a paper on initial findings and analysis, but I am having a lot of trouble in how I...
8. ### Correlation and ROC analysis with repeated measures data

Hi all, I have a hypothetical study where participants are taking drug X per standard of care. I have 3 different timepoints (baseline, therapy, post-therapy follow-ups) at which participants have biomarker sampling and echocardiograms performed. Exploratory objective: efficacy; Exploratory...
9. ### Correlation to ratio of two variables from individual correlation.

I am trying to estimate the correlation between three parameters, from some know correlations between some of them. I know the correlation of two variables Corr(k,1/a), Corr(k,1/(a+b)). How can I calculate Corr(k, (1/(1-(b/a)))? Also, if the two known correlations [Corr(k,1/a)...
10. ### Spearman Rank + Quadratic Regression (spps) HELP! x

Hi, I'm trying to find out if there is a significant correlation between salinity and no. of Bivalves found on a shore. I did a Spearman Rank and this was my result: "There was a statistically significant correlation between Salinity and the number of Bivalvia individuals (Spearman Rank...
11. ### Association between non-normal continuous variable and dichotomous variable

Hello, I'm trying to examine the association between a non-normally distributed continuous variable and a dichotomous variable: yes/no. At first, I thought I should conduct point-biserial correlations but then I realised that in point-biserial correlations, the continuous variable needs to be...
12. ### Which correlation coefficient is best suited to dichotomous variables (and why do my results feel intutiteivly wrong)

I have collected data that shows the days on which I fasted and if those days resulted in weight-loss. Null hypothesis: There is no statistically significant relationship between fasting and weight loss. Data Analysis: 1 The chart (see way below) is a visual representation of my data. The...
13. ### Correlation with unknown numbers

I am looking at a data set that can correlate prior doses of drug A with the amount of time (in days) before developing infections after stopping drug A. We hypothesize that people with lower dose will have longer latency before developing infections. But we have a lot of people (especially...

Reporting
15. ### University project help (correlation)

Hello dear stat-folk! I'm currently in the process of re-writing my project due to a failed exam in it. In this regard i'm having trouble figuring out whether i can even use statistics (and how) to describe a theory i have towards a possible correlation. In this part of the project i am...
16. ### Advice on which analysis to use for count data...

I am looking to examine whether one variable (counts of social interactions) is associated with another variable (counts of running activity). Both variables are simply frequency counts of behaviours which were counted at the same time during 40 hour-long observation periods across two weeks...
17. ### Comparing correlation coefficients

Hello, I have a large sample of patients who have had a TIA, minor stroke or major stroke. I have been looking at correlations in each of these three groups. Is there a statistical test in SPSS (or elsewhere) that would allow me to compare the correlation coefficients between each of three...
18. ### panel data correlation

Dear All I want to study the effect on ROA for a pharmacy that has an online pharmacy department compared to pharmacies that don't. This is my regression: Return on assets = b0 + b1*ln(total assets) + b2*ln(firmage) + b3*leverage + b4*current ratio + b5*dummy online pharmacy + b6*dummy online...
19. ### Can a ratio of performance be used to measure dependence and assign weights in a weighted average?

With only a modest grasp of inferential stats and maths in general, I've been wondering how one might derive the weights for a weighted average from a variable that isn't as straightforward as a frequency score. Consider the following scenario. Let's say I have measurements of effectiveness for...
20. ### Test for Multicollinearity

Hello Talk Stats Forum! I am working on building a Predictive Model using the binary logistic regression and LASSO logistic regression. In order to apply these models on some real data set I am using R software. Before performing such a model I am testing for multicollinearity and will remove...