You'll know that you need information when you:
- get a project/assignment from a lecturer
- having a personal need that requires certain information before
you can make a decision, e.g. buying a car.
Generally, whenever you are uncertain you could find information that
will help you take the correct decision.
Remember that one needs information not just for study purposes, but
for most decisions in everyday life. You make decisions every day, whether
it is to buy a car, house or do a project or assignment. You need information
to make good decisions.