What is the difference between causality and correlation? Give an example to illustrate the difference.
Correlation explains the relationship between variables. Correlated variables are considered to be related, and changes in one variable are followed by changes in another. For instance, an increase in school attendance is aligned with an increase in exam success rate. While correlation defines the relationship between variables it doesn’t explain whether one variable has an influence on another. In the same example, we are not able to establish a causal relationship clearly. Thus, it’s difficult to say whether students with better class attendance would pass more exams or vice versa students who do better on exams put more efforts on attending the classes. Causality defines the dependence of changes in one variable from another. For instance, when we measure the quantity of sugar in the cookie and its sweetness, it is clear that the degree of sweet taste is a result of changes in the quantity of sugar in it (if all other ingredients remain same in proportions and content).