The Montessori educational philosophy is built upon the idea that children develop and think differently from adults; that they are not merely "adults in small bodies". Dr. Montessori advocated children's rights, children working to develop themselves into adults, and that these developments would lead to world peace.
The Montessori method discourages many of the traditional measurements of achievement (grades, tests). The method instead focuses on sparking a child's interest in learning through presenting materials to students that will catch their interest. The Montessori Method does measure feedback and qualitative analysis of a child's schooling performance. The analysis does not come from grades, but from careful observation of the child.
Montessori teachers do evaluate children's progress: when giving lessons, through ongoing observations in the classroom, by examining the products of their work, and by going over the Work Journal. It is simply not often obvious to children that they are being evaluated, since they are not given grades, praise, or other tokens of evaluation.
There are many ways to present these observations to parents and there is no standard way to do it. It is often recorded as a list of skills, activities, and critical points, and sometimes including a narrative explanation of the child's educational achievements, strengths, and weaknesses — with the emphasis upon the improvement of said weaknesses.