My essay

It has been said, “Not everything that is learned is contained in
books.” Compare and contrast knowledge gained from experience
with knowledge gained from books. In your opinion, which source
is more important? Why?

Answer to the question regarding importance of source of the knowledge depends on the choice of the field of knowledge. For example if the question is regarding knowledge in biological science, apparently books are the most-important source. On the other hand, experience plays a more important role in knowledge related to skills of life. As a matter of fact, sometimes experience teaches things which contrast what is written in books. Let me explain this in an example. A friend of mine recently moved to a new city to work in a hospital. His supervisor discriminated against him and finally discharged him allegedly for “Poor Performance”. He followed the textbook procedure and filed a complaint with the related agency. According to the books, discrimination is wrong and has consequences. In reality, he learned that he might not be able to get his right if he is not able to afford a good lawyer. In other terms justice is sold, sometimes at a high price and if you can not afford it, you might lose your case. In other terms, additional complicating factors are involved in the process. Financial power of your opponent is one example. Threshold of society for discrimination is another factor. Some societies are more tolerant towards discrimination and it is much harder to convince people that harm is actually done. Length of time and level of efforts needed to prove a fact also play role.
One important difference between experience and book-acquired knowledge is the time required to gain the knowledge. In contrast to reading a book, experience is gained gradually. For example, one who studies traffic signs and rules and passes a driving test has a lot to learn over a period of years to become an experienced driver.
Another difference between these two sources of knowledge is the level of complexity of the matter. Experience usually teaches how to solve equations with more variables. In the driving example, a new driver who passes the test will be exposed to lots of complicated situations over time. He will face lots of challenges which are not explained in the book. He needs to learn to drive in rain and storm. His car might break up. He might experience an accident. He will learn how to cope with drivers that might violate rules.
In summary, compared to the book-derived knowledge, experience deals with more complicated situations and teaches through a more gradual process. It usually complements knowledge gained through reading books over time.

TOEFL listening lectures: Which is a characteristic of realistic landscape paintings?