HOW ARE LISA'S GRADES CALCULATED?
LISA grades a student's answer by reading their writing (several times) and asking a number of specific questions, e.g. is there a central idea, are their supporting ideas, does the student use paragraphs, are there examples of complex punctuation, etc.
Each of these questions relate to an aspect of writing typically expected at a certain age. LISA then averages these "micro-grades" into sub-conventions, conventions, and overall grade.
As we accumulate more examples of students' work and use contracted teachers to moderate LISA's marking, the algorithm for calculating grades will grow more sophisticated.