correlation

  1. L

    Finding correlation for penalized regression in R

    I need to use the penalized models (lasso, ridge) for linear regression. In R, I use the "penalized" package. The output is a penfit object. If I want to find the in-sample and predictive correlation, how can I do that in R? Converting the penfit oject to glm maybe a good idea,but I don't...
  2. M

    bootstrapping correlations Spearman vs. Pearson

    I would like to calculate simple correlations. Since my sample size is quite small and data are not normally distributed I thought about Spearman’s correlations. Then I read about bootstrapping as a distribution free method and, considering my small sample size, I decided to use it with...
  3. R

    PCA (correlation) Biplot - correlation and angles

    Hi, I have a question regarding a PCA correlation Biplot. As far as I understand, angles between lines are (approx.) correlations between corresponding variables. Especially, if the angle is about 90° between two lines, these two variables are uncorrelated. But how does the plot look like if...
  4. I

    Correcting for regression to the mean in mixed effects model of longitudinal data?

    Hey everyone, I know you can correct for regression to the mean for two time points, in a before and after scenario. But does anyone know how to do this when there are more than two time points, let's say there are about 10 points in a time series. I was hoping to model the longitudinal data...
  5. D

    Generating random data from correlations

    Say I have a list of personality traits: courage, materialism, compassion and so on. I interview some people and assign a rating from -10 to +10 to each trait for each person, then I find the correlation between each pair of traits. Now I want to create a "random person" by assigning a value...
  6. C

    Can you perform an ANOVA on r-values (correlation values)?

    Hi all: This may be a simple question but... I'm doing neuroimaging research and long story short, I am doing what is essentially a correlational analysis wherein my output is a brain's-worth of r-values (so like 15000 voxels worth of r-values). In this particular study I had 3 groups and I...
  7. C

    Difference between two lmer model .

    Can you please explain where is the difference between the following two models : fm1 <- lmer(Reaction ~ Days + (Days | Subject), sleepstudy) fm2 <- lmer(Reaction ~ Days + (1|Subject) + (0+Days|Subject), sleepstudy) I noticed there is some discrepency in the estimate for random effect...
  8. L

    Types of interactions

    Hi, I am stuggling to find the right words for the statistical terms I would like to look up. Hope, you can help :-) I am looking at a higher order construct (organizational climate), which manifests in eight dimensions. I am interested in elaborating how these dimensions interact and what...
  9. K

    confidence intervals for correlations on AMOS or SPSS

    Hello, I was wondering how to calculate confidence intervals for a correlation coefficient on Amos or SPSS. I've been trying to do it on SPSS by standardizing my data, but i've been told the estimate is not fully accurate. When i try to do it on Amos, i get the correlation coefficient but no...
  10. A

    Help with interpretation

    Hi All, Here is what i need help with. I am working with small sample size and this is the result so far. X and Y are not correlated ; however, when I place X in a stepwise multiple regression predicting Y, alongside three (A, B, C) other (related) variables, X and two other variables (A...
  11. K

    Statistical test for comparing means of correlation coefficients

    Suppose that I have two lists of correlation coefficients such as A = [0.5,0.3,0.25,0.3,-0.1] and B = [0.8,0.7,0.75,0.8,0.8]. The correlation coefficients in A are independent to B. Now, I want to test the null hypothesis, that the means of both lists are equal. I am familiar with how to...
  12. M

    Statistically compare 2 3D structures

    G’day Statistics Forum I’m having a little bit of trouble with the statistical analysis segment of my honors thesis proposal and was hoping one of you helpful folk might be able to offer some insight. I believe this sounds more complex than it actually is, so bear with me cause I am really...
  13. S

    Predictive model for Turnover - Correlation or Survival Analysis

    Question 1 - I a working on developing a model to predict employee turnover. The variables that I have are age, tenure, job satisfaction, role clarity etc. Through research papers I have found the correlation coefficient for these variables but I am not sure on how to develop a model around it...
  14. E

    How to do Kendall test with ordinal data

    Hi, I have the following profitability data: 1) Rankings of profitability for customers: 1, 2. ... 15 2) Categories of same customers, grouped after profitability (from 1 to 5): 5, 5, 5, 3, 4, 5, .... 5, 4 (15 in total) I have troubles finding the Kendall Tau...
  15. M

    software speed

    Not homework BTW ... I want to measure the processing time (performance) of some software under a set of fixed conditions. I have a means to log the start and stop of the processing. The only possible factors are some uncontrollable (noise) factors, e.g., the CPU and memory usage. Then there is...
  16. L

    Can correlation be used as a measure of accuracy?

    I have a paired data set of known age and estimated age, and correlation tests show that there is a strong correlation between the two, but what I want to know is, does that mean the estimates are accurate? My thinking is no, correlation cannot tell you if the estimated age is accurate, but...
  17. T

    Trouble comparing variables in SPSS to one set of rules

    Hi guys! I am a little puzzled. :confused::confused: I am carrying out research on cyclists perceived benefits of the supplements they take and comparing them to what is scientifically proven. So far I have inserted all my data into SPSS and I have grouped all the variables accordingly...
  18. A

    Average individual correlations or perform 1 set of correlations

    First of all thanks for your time reading this post. I got some issue with correlation analysis that I am not able to solve at all as for more people I ask, different opinions I get (including opinions read on this forum). I will try to explain my situation: I go 1200 data from different...
  19. J

    One-way ANOVA and planned comparisons - HELP!

    Hi all, I'm currently running a Psychology experiment: the effect of background music on memory and mood. I will be using SPSS to conduct two one-way ANOVAs (music + mood / music + memory), w/ planned comparisons. However, I also want to see the effect of mood on memory but I don't know how...
  20. A

    Panel data correlation

    In a panel dataset of multiple years and multiple countries, what is best practice for running correlations among variables? I know that pooling by both countries and years is not recommended. Is restricting instead by both country and year the preferred method? Or just by either one, country...