Definition Coefficient of correlation
In statistics, a coefficient of correlation reflects the strength and direction of a linear relationship or dependence between two cardinal or ordinal variables. The correlation coefficient always lies between -1 and +1. A value of -1 indicates an entirely negative correlation.
An example of a positive correlation can be seen in the level of education and salary. Usually, a person with a higher education level (a university degree versus a high school diploma) also has a higher salary at work. Thus, it is possible to say that the level of education correlates positively with salary. An example of negative correlation can be seen in the size of a file and speed of a computer opening it. When you use the same device to open the same format of file, the larger the size of the file, the slower the laptop will be in opening the file. Thus, it is possible to say that file size and speed of opening a file on the same device correlate negatively.
Please note that the definitions in our statistics encyclopedia are simplified explanations of terms. Our goal is to make the definitions accessible for a broad audience; thus it is possible that some definitions do not adhere entirely to scientific standards.