Frequently Asked Questions

Our FAQ page continues to evolve in response to questions from the users of MRS-EC-E. The FAQ are both general and organized by item. High inter-rater reliability is achieved through this process.

How long does it take to rate a Montessori classroom?
    • MRS-EC-E requires a 2½ hours observation period, typically. A less experienced Montessori teacher may require more time.

      The Rater completes the observation, then an interview with the head teacher Is conducted for about 30 minutes, to clarify substandard items in particular.

      It would be possible to do the observation in shorter periods over the course of several days; however; the scores may not be reliable. In many ways the scales are time samples – to see whether things happen frequently enough for them to make a developmental difference to children. That is why for some items there are places where it specifies that the requirement must be observed at least once, or perhaps more, during the observation. If a teacher is given three different opportunities on three different days to show that behavior, it may be given credit, while if the observation had been done in only one morning, it might not.


Can the rating take place over the course of several days?
    • MRS-EC-E may be conducted over several days during a seven day period.
Can higher-level indicators be scored if lower-level ones have not been met?
    • No, all scoring criteria below the score selected must be met. Each item’s criteria is inclusive of the lower level score options.
What does extension mean?
  • Extension is an activity that expands or extends the child’s experience. The activity may be in the form of a material displayed approximate to the material being scored, or an experience that the teacher exposes the child. In the latter situation, a picture of such activities documents the extension.
Where can the scales be purchased?
  • You can purchase the scales through Montessori Research & Development at this link.