An intervening variable facilitates a better understanding of the relationship between the independent and dependent variables when the variables appear to not have a definite connection. They are studied by means of operational definitions and have no existence apart.
Macroevolution is the process that takes place over several thousands of years and describes how humans have evolved from primates and how reptiles turned into birds. Microevolution leads to small changes in the same species whereas macroevolution leads to the creation of a new species from parent species.
Difference between CPVC and PVC. â¢ While PVC is the most widely used thermoplastic polymer, CPVC is a recent phenomenon created by chlorination of PVC. â¢ PVC is still more popular than CPVC which is more expensive. â¢ CPVC is better suited under certain conditions such as transport of hot and cold liquids.