Variables are must be correlated( Ex: Education level of parents are found to be correlated to the education level of their children) Cause takes place before the effect. „ Example: Education level of parents usually is determined BEFORE the education level of their children. Thus the education level the education level of their children. Thus the education level of parents of parents is likely to be the cause in this relationship. „ Effect cannot be explained in terms of a third variable Effect cannot be explained in terms of a third variable (nonspurious). (nonspurious). Example of a spurious relationship: Ice cream sales are positively correlated with number of people drown at the beach. And ice cream eating happens before the drowning. But is eating ice cream causing people to drown? No, because there is a third factor: hot weather. Hot weather cause ice cream consumption to go up, and number of people swimming to go up at the same time. Hot weather, in this case, has caused a spurious relationship between ice cream consumption and number of people drown.