Questions tagged [pearson-r]
The Pearson product-moment correlation coefficient is a measure of the linear relationship between two variables $X$ and $Y$, giving a value between +1 and −1.
539
questions
5
votes
1
answer
178
views
What references discuss the problems with phi as an association measure?
(Olivier (2013) states that
many have pointed out problems with $\phi$ as an association measure and advocate the use of odds ratios as an alternative
Unfortunately, it does not give citations for ...
- 939
0
votes
1
answer
58
views
Pearson & Spearman correlation coefficient in their extreme
I am working right now in R with correlation coefficients. I know that we can achieve approximately a Pearson coefficient r=0 and Spearman p=1, because Pearson is sensitive to outliers. However, I was ...
- 121
2
votes
3
answers
415
views
When to use Pearson's test and when to use Spearman's test?
I want to do a correlation analysis on a dataset of 28 samples.
I want to correlate the age with the size of a reflex response.
But I don't understand whether I should use Pearson's or Spearman's test....
- 21
3
votes
1
answer
30
views
Deducing from Ordinal to Binary Data
Assume I have two rank vectors $r^A, r^B$ of size $p$ - that is, each of them is some permutation of $1,...,p$. For the sake of simplicity, assume that $p$ is odd.
Now, I take these vectors and recode ...
- 4,032
3
votes
3
answers
2k
views
Pearson or Spearman? [duplicate]
After using the Shapiro-Wilk test for Bivariate Normality, I found different values of p. For the ones which were p<0.05 I used Spearman and the ones which were p>0.05 I used Pearson. Is it the ...
- 47
3
votes
0
answers
33
views
How do zero values affect the correlation between two twitter activity time series?
I have a time series of Twitter activities (lets call it time series 0) from which I extract two separate time series based on different sets of users (i.e. time series 1 contains the activity of a ...
- 41
0
votes
0
answers
56
views
Can I do Pearson cross-correlation between two time series of Twitter data without violating the assumptions?
I have a dataset of Tweets regarding a given topic (extracted by predefined keywords and hashtags). I aggregated the Tweets in bins of time (e.g. every ten minutes) to generate a time series of the ...
- 41
3
votes
3
answers
215
views
How to decorrelate $X$ and $X^3$?
We know that if $X$ is positive, then $X^2$ is highly positively correlated with $X$.
I've plotted an array of integer numbers from 100 and 110 with the following code:
...
- 53
1
vote
0
answers
45
views
If X is positively correlated with Y and Y is positively correlated with Z, it is still possible for Z to be negatively correlated with X? [duplicate]
This is not assuming a perfect correlation between variables. I believe that the answer is yes as long as r<1.0. (r = Pearson product-moment correlation coefficient.)
Bonus: if the question is ...
- 171
1
vote
1
answer
57
views
What statistical test should I use for my dataset - Pearson's or Spearman's?
I'm not quite sure what statistical test I should be conducting for my dataset. I am aiming to find the correlation between two variables (concentration of copper vs concentration of chlorophyll). My ...
- 11
1
vote
0
answers
44
views
Yes or no: is Pearson’s r is a measure of goodness of fit to an affine function? [duplicate]
Is the statement "Pearson’s r is a measure of goodness of fit to an affine function" literally true? Why or why not?
- 171
6
votes
3
answers
6k
views
The meaning of the p-value for a correlation coefficient
Recently, I learnt that one can also calculate a p-value for the Pearson correlation coefficient. My question is not about computation of this p-value. (Based on what I read from other posts, we first ...
- 163
1
vote
1
answer
26
views
Testing for correlation
I'm new to statistics. I'm solving a problem where I'm given three sets of data, the measured sizes of the population of rabbits, the drug dose that's been given to each of them and the method of ...
- 193
0
votes
0
answers
33
views
Selection of covariates for partial correlation?
Are there any recommendations on procedures to identify relevant variables for a partial correlation between $r(X, Y)$?
To me, it appears most reasonable to only include those $Z_1, Z_2,\ldots,Z_n$ as ...
- 415
0
votes
0
answers
12
views
correlation that is less sensitive to neighboring class changes
I am calculating the correlation between the scores a radiologist attributes to an MRI image (discrete 0,1,2,3), against the continuous quantification of disease (continuous between 0 and 1). I see a ...
- 101