You will be given a definition of a task first, then some input of the task.
In this task, we ask you to rewrite a sentence in simple English without changing its general meaning. Essentially, you want to make the sentence easier to read by using simpler words, utilizing more straightforward sentence structures, and omitting non-essential information etc.

The most familiar measure of dependence between two quantities is the Pearson product-moment correlation coefficient , or " Pearson 's correlation coefficient " , commonly called simply " the correlation coefficient " .
Output:
The best known is the Pearson product-moment correlation coefficient .