Why is Charlie writing progress reports in Flowers for Algernon?

As a thirty-two-year old intellectually disabled man with an IQ of 68, Charlie Gordon has agreed to undergo experimental neurosurgery which will dramatically improve his intelligence. In order for Dr. Strauss and Professor Nemur to monitor Charlie's intellectual and emotional development and progress, he must undergo a series of tests and compose daily progress reports. The progress reports will serve as a record of Charlie's intellectual improvement when the doctors compare them before and after surgery. Initially, Charlie's progress reports are difficult to read, and there is a litany of grammatical and spelling errors which indicate that he is an intellectually disabled man.
Following the neurosurgery, Charlie ends up beating the experimental rat named Algernon in several mazes, and his intellectual development is revealed in his progress reports. Although Charlie does not enjoy writing his progress reports, they serve an important function, as the reader gains insight into Charlie's dramatic transformation. His progress reports also reveal his traumatic past and complex emotions. Overall, Dr. Strauss and Professor Nemur require Charlie Gordon to write progress reports, which serve as a record of his intellectual development when they compare the reports before and after the surgery.