John Dewey thought that children will learn better through participating in experiences.
What is the wrong here? and why?

Question

Answer

John Dewey thought that children WOULD learn better through participating in experiences.

If you say "thought" you MUST use the one-tense-back-rule.

Othewise:
John Dewey was of the opinion that children will learn better through participating in experiences.

Answer

"What is the wrong"... so incorrect that I must use it. :)

Answer

Is johnny still alive? :P