blue bookは一般的には「（国会または政府の報告書）清書」（cf. white book）を指しますが、「(大学の記述式試験答案用)青表紙の白紙帳」という意味があります。（UG）
Essay-Grading Software Offers Professors a Break
Imagine taking a college exam, and, instead of handing in a blue book and getting a grade from a professor a few weeks later, clicking the “send” button when you are done and receiving a grade back instantly, your essay scored by a software program.
"What is the crime in waiting two weeks for a professor's thoughtful and accurate essay grade? [A]n essay certainly doesn't take an instant to craft, so why should the grading be quick and dirty?"
EdX, the nonprofit enterprise founded by Harvard and the Massachusetts Institute of Technology to offer courses on the Internet, has just introduced such a system and will make its automated software available free on the Web to any institution that wants to use it. The software uses artificial intelligence to grade student essays and short written answers, freeing professors for other tasks.