48 views

### Which correlation formula should be used when we add up many measurements of the ordinal type?

Let's say, I have two set of questions; one set is to detect depression (var1) where the response of each question is in Likert scale and another set of questions to detect hopelessness (var2) where ...
380 views

### How to choose a correlation measure when Pearson is close to 1 and Spearman close to -1?

I have two large datasets from nonlinear control systems. I am trying to correlate the error with the control action taken. If the error is plotted as fx and the control action as fy we end up with ...
2k views

### Normal Distribution for Pearson Correlation

I have read that the variables must be approximately normally distributed to apply Pearson correlation; However, I came across this answer here that they dont need to be, so I am confused about ...
2k views

### Pearson correlation between a variable and its square

Here is my R code to get familiarised with Pearson's correlation. I generate values of $X$ from 1 to 100, then find the correlation between $X$ and $X^2$: ...
964 views

### Should I use Pearson or Spearman correlation?

I have to know the correlation between 2 variables (bivariate distribution). None of them are normally distributed, so I assumed that I should run Spearman's correlation, which gave me a correlation ...
997 views

### Pearson and Spearman correlations [duplicate]

I'm having a problem with choosing between Pearson and Spearman correlation. I'd like to understand clearly why I should use one or the other. I have read the questions already asked here about this ...
120 views

### What metric to calculate correlation between average user ratings of products?

What's the best method to see if there's a strong correlation between two types of ratings on a product level (product $1, 2, \dots, n$) where each product has ratings of type '$a$' and '$b$'? For ...
42 views

### Correlation indexes in medicine

My father is a doctor and he asked me to find out if there is a correlation in two sets of data he collected, one concerning the age of his patients and one concerning the value of a medical exam I ...
461 views

### Correlation between ordinal and ordinal variables

My study is aim to show the correlation between the Prostate MRI Scoring and Prostate Pathology Gleason Scores. For prostate MRI Scoring system (PIRADS) we score lesions according to their MRI finding ...
2k views

### bootstrapping spearman vs. pearson multiple correlations

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 ...
148 views

### What kind of statistical test is appropriate for this?

Variable X designates a group label (group 1, group 2, etc). Each group represents an amount of time spent watching TV. For example group 1 might watch TV less than an hour a week, group 2 watches 1-2 ...
17k views

### Correlation using Logistic Regression and Pearson

I am so sorry, I am beginner in statistic analysis, I have project using R to analyze the correlation between dependent variables and independents variables. In this case I have two dependent ...
942 views

### Is it a reasonable rule of thumb to examine Pearson and Spearman correlations, and use the latter if they are very different?

The data I am using is continuous, and may be somewhat skewed, but probably will not have many outliers. The following rule of thumb has been suggested to me: examine both Pearson and Spearman ...