Positive Correlation

An average association between two variables in which, as one variable increases in value, the other variable tends to increase in value; and as one variable decreases in value, the other variable tends to decrease in value.

Example 1
The speed at which a car travels is positively correlated with the probability of the car being involved in an accident: the faster the car travels, the greater the probabilty that the car will be involved in an accident.

Example 2
The distance a student's seat is from the front of the classroom is positively correlated with the student's overall course score: the closer the student sits to the front of the classroom, the higher the student's overall course score tends to be.

See: negative correlation