Achievement at MIR is based on the social, emotional and intellectual progress of each student. Therefore, assessment is not solely based upon test scores and grades, which reflect a limited aspect of intellectual ability and progress. Evaluation of student progress relies heavily on observation and verbal interaction as well as on work product. The entire staff establishes a school culture of high expectations for themselves and the students.

Montessori teachers assess the academic, physical, social, emotional and developmental progress of the child. Specially designed classroom materials, presentation sequences, teacher observations, student recordkeeping and student work are part of the daily assessment of progress that is woven into the fabric of the Montessori classroom.