The correlation coefficient, plus graphical methods to verify the validity of a linear relationship (which is what the correlation coefficient measures), and the appropriate tests of the statisitical significance of the correlation coefficient.
It tells you how strong and what type of correlations two random variables or data values have. The coefficient is between -1 and 1. The value of 0 means no correlation, while -1 is a strong negative correlation and 1 is a strong positive correlation. Often a scatter plot is used to visualize this.
If measurements are taken for two (or more) variable for a sample , then the correlation between the variables are the sample correlation. If the sample is representative then the sample correlation will be a good estimate of the true population correlation.
Evidence that there is no correlation.
They can be positive correlation, negative correlation or no correlation depending on 'line of best fit'
It is not possible to use correlation when the two variables are not related at all. the corelation coefficient value that will be obtained will have no significance.
There is no significance or correlation between gay people and teachers.
The correlation coefficient, plus graphical methods to verify the validity of a linear relationship (which is what the correlation coefficient measures), and the appropriate tests of the statisitical significance of the correlation coefficient.
It tells you how strong and what type of correlations two random variables or data values have. The coefficient is between -1 and 1. The value of 0 means no correlation, while -1 is a strong negative correlation and 1 is a strong positive correlation. Often a scatter plot is used to visualize this.
See Terrell, C. D. (1982). Significance tables for the biserial and point biserial. Educational and Psychological Testing, 42, 975-981.
Auto correlation is the correlation of one signal with itself. Cross correlation is the correlation of one signal with a different signal.
positive correlation-negative correlation and no correlation
No. The strongest correlation coefficient is +1 (positive correlation) and -1 (negative correlation).
The correlation can be anything between +1 (strong positive correlation), passing through zero (no correlation), to -1 (strong negative correlation).
Trends, covariance, and correlation are the big ones. Statistical significance, unit roots, heteroskedasticity, and format and source of the data would affect quality too.
If measurements are taken for two (or more) variable for a sample , then the correlation between the variables are the sample correlation. If the sample is representative then the sample correlation will be a good estimate of the true population correlation.
No.