An article by eSchool News discusses the importance of writing to improve student learning in all disciplines, not just to prove students are learning.
"Simply put, writing is our critical thinking made visible.
"Through the process of writing, writers put nascent thoughts into comprehensible language for others to read. In their pursuit of self-expression, they often find themselves challenged to find new words or motivated to develop academic vocabulary.
"Because it is a critical thinking process, writing isn’t merely an act of jotting down what you have in your head. Once the initial thoughts in your head start to flow, you naturally begin iterating on them."