Answer:
because things like knowledge are not physical, tangible things, measuring them can prove more difficult. If someone tells you they are smart, there is no way to prove them right or wrong unless they are able to demonstrate and support their claims. This is why we use standardized tests and assignments in order to give people and students a way to demonstrate their knowledge. On the other hand, standardized tests often prove an unreliable way to measure intelligence as not everyone is the same in terms of ability to perform and prove their claims while others may be considered just as smart in other areas and subjects.
Step-by-step explanation:
I know this question was posted awhile ago but i thought id still answer in case someone else who needed it came across it.