By Angeline S. Lillard, Professor of Psychology at the University of Virginia and Justus Randolph, Professor of Nursing at Mercer University
Montessori education’s impact on academic and nonacademic outcomes
Montessori education has lasted for over a century, and is by far the most widespread alternative to traditional, teacher-centered, age-graded and grade-based education. And yet we do not know if it works. For example, a recent Psychology Today article, as well as a BBC story, both reported that there is insufficient evidence to know what difference it makes to children’s lives.
A new Campbell systematic review aims to answer that question. Campbell reviews are a gold standard for transparent summaries of all the research on one question. The methodology is planned, peer reviewed and published before work starts. The review itself is also peer reviewed by leading experts before publication.
The Campbell systematic review of 32 studies, all of which demonstrated the groups were comparable at baseline, showed that Montessori education has a meaningful and positive impact on children’s outcomes. Evidence of baseline equivalence was established through random assignment, statistical control, or at pretest.
Montessori affects both academic and nonacademic outcomes
The review showed that Montessori had impacts on both academic and nonacademic outcomes, compared to traditional education. On academic outcomes, the average effect size was about a quarter of a standard deviation, estimated to be equivalent to a whole school year in 6th grade. Specific academic effects, which were positive and significant, included language, math, and general academic ability. Montessori did not have a significant impact on science or social studies; however, only four studies contributed effects to those outcomes.
For nonacademic outcomes, the average effect was about a third of a standard deviation. Children attending Montessori had stronger executive function (self-control, working memory) and a more positive experience of school. Their social skills showed a trend towards being stronger, and their creativity was not significantly different from that of children receiving traditional pedagogy. Even on these latter two outcomes, Montessori had an impact of about a quarter of a standard deviation, yet studies varied a good deal in the strength of the effect.
Global diversity characterizes Montessori students and studies
Although the majority of the studies in the review were conducted in the USA, they also took place in countries as diverse as Turkey, Malaysia, Oman, Iran, Thailand and Switzerland. Although there was insufficient information for analysis, a full range of socio-economic classes was represented among the studies. More than half of the students in public Montessori schools in the USA are students of color.
Effects vary by age level, school type and study type
Montessori education had a stronger impact on preschool and elementary school children than on middle and high school children. However, there were fewer studies of children at older ages. Montessori also had stronger effects at private schools than at public ones. One potential reason is that public Montessori schools are often asked to compromise the pedagogy to fit district requirements; although theoretically, such adjustments could improve the pedagogy.
Results are also stronger for studies using random assignment, many of which were conducted at public schools. A possible reason for this is that few studies use random assignment, and some of those that did were at Montessori schools with very strong implementation (recognized by the Association Montessori Internationale, the organization Maria Montessori founded in 1939 to carry on her scientifically-based pedagogy).
Studies in the review reflect a range of Montessori implementations, reflecting the variety of Montessori implementations in the world
Montessori is not trademarked, and implementations therefore vary in the real world: anyone can claim that their school is a Montessori school. The very best schools have teachers trained by highly respected organizations like the Association Montessori Internationale. The best schools also have complete sets of special hands-on learning materials designed by Montessori and her collaborators. Children receive carefully tuned individual or small group lessons and then can freely interact with these material for long (2.5-3 hour) uninterrupted periods of time; as children get older they constantly carry on extensive research projects, which they present to the class. Classrooms have three age levels, and there are no grades nor homework.
Not all the studies in the review discussed implementation, and a few clearly deviated from one of more of these principles, yet still the results on every variable were positive on average, suggesting that Montessori as it is implemented in the real world generally has positive impacts.
Researchers should more carefully document implementation fidelity to allow this variable to be considered in later reviews.
Summary
Montessori education appears to have a positive impact on children’s academic and nonacademic outcomes.
Note: Soon after this review was accepted for publication, another meta-analysis of Montessori education was published, using different search criteria and methods but obtaining very similar results.