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Quality preschool programs that develop the whole child through age-appropriate socioemotional and cognitive skill-building hold promise for significantly improving child outcomes. However, preschool programs tend to either be teacher-led and didactic, or else to lack academic content. One preschool model that involves both child-directed, freely chosen activity and academic content is Montessori. Here we report a longitudinal study that took advantage of randomized lottery-based admission to two public Montessori magnet schools in a high-poverty American city. The final sample included 141 children, 70 in Montessori and 71 in other schools, most of whom were tested 4 times over 3 years, from the first semester to the end of preschool (ages 3–6), on a variety of cognitive and socio-emotional measures. Montessori preschool elevated children’s outcomes in several ways. Although not different at the first test point, over time the Montessori children fared better on measures of academic achievement, social understanding, and mastery orientation, and they also reported relatively more liking of scholastic tasks. They also scored higher on executive function when they were 4. In addition to elevating overall performance on these measures, Montessori preschool also equalized outcomes among subgroups that typically have unequal outcomes. First, the difference in academic achievement between lower income Montessori and higher income conventionally schooled children was smaller at each time point, and was not (statistically speaking) significantly different at the end of the study. Second, defying the typical finding that executive function predicts academic achievement, in Montessori classrooms children with lower executive function scored as well on academic achievement as those with higher executive function. This suggests that Montessori preschool has potential to elevate and equalize important outcomes, and a larger study of public Montessori preschools is warranted.
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Optimizing preschool education is important from both economic and developmental standpoints (
Montessori education aligns with principles and practices that a century of research has shown are more optimal for child development than the principles and practices that undergird conventional schooling (
The first studies of Montessori outcomes lacked good controls or had small samples and compromises in program quality; for example, they used single-age classrooms, added non-Montessori activities, and/or had teachers with minimal training (
Another study avoided these problems by testing 5-year-olds in a high-fidelity public inner-city Montessori school who had gained admission through a computerized district-level random lottery when they were 3 years old, and compared their outcomes to those of 5-year-olds who had lost that lottery and were at non-Montessori schools (
In the present study, children in two high-fidelity public Montessori magnet schools (11 classrooms) who had gained admission via a random computerized district-level lottery at 3 years old were compared to a group who had lost the lottery and attended other non-Montessori schools, over half of which were private schools. Children (
Children’s academic ability is considered of primary importance in school assessments. For young children, initial progress in reading, vocabulary, and numerical understanding are valued indicators. Here we measured these with four Woodcock–Johnson IIIR Tests of Achievement: Letter-Word, Picture Vocabulary, Applied Problems, and Calculation (
Academic benefit might have trade-offs in social learning; indeed, Montessori education has been criticized for being “asocial” since the children rarely participate in whole-class activities (
Although theory of mind is related to social competence, they are different constructs. Social competence was measured more directly with stories from the Rubin’s Social Problem-Solving Test - Revised (
Theory of mind is also strongly associated with executive function and involves many of the same neural structures (for example the medial and lateral prefrontal cortex and the temporo-parietal junction) (
In addition to academic achievement, theory of mind, social competence, and executive function, which have been examined previously, we also used three tasks not previously used in studies of Montessori preschool. The first was the growth of a mastery orientation. Mastery orientation is an important personal quality (
The second new construct was feelings about academic tasks. Early academic achievement might occur at the expense of enjoying school tasks, which is undesirable since enjoying kindergarten predicts later school achievement (
Another measure not used in prior studies of Montessori outcomes was the Alternate Uses task, which assesses creativity. Creativity is certainly a desirable construct. Because conventional educational methods often require children to answer questions in specific ways (as on multiple choice tests) but Montessori often encourages independent exploration, Montessori might promote more creativity. On the other hand, there are particular ways that children are instructed to use specific Montessori materials, and this could discourage creativity. Alternate Uses (sometimes called Creative or Unusual Uses) is a commonly used task that asks one to come up with as many uses as one can for common items like paper clips and towels (
In sum, the study measured children’s academic achievement, theory of mind and social skills, executive function, mastery orientation, relative enjoyment of school, and creativity at four time points to determine whether Montessori education would have a significant influence on those important constructs.
In addition to examining the overall efficacy of Montessori preschool for these measures, the study (because of its sample size) permitted examination of Montessori’s potential for disrupting the predictive power of certain variables for certain outcomes. One is the predictive power of income for achievement, or the income achievement gap. Childhood poverty is a significant predictor of poor life outcomes (
The samples were ethnically diverse and equivalent at the first test point in terms of parent education and income (ranging from $0 to $200,000), child age, and Time 1 scores; this lack of pre-existing differences would be expected given the random lottery assignment. Slight (but non-significant) differences in performance at Time 1 could be due school programs already having influenced children at the first test point, which ranged from mid-September to mid-December. Over the subsequent 30 months, significant differences emerged on several measures, all indicating better outcomes for children in the Montessori program.
This longitudinal study examined how children in Montessori vs. other preschool environments changed over 3 years. The same basic set of tests were administered to children at each time point. The study was carried out in accordance with the guidelines for human research of the Institutional Review Board for the Social and Behavioral Sciences at the University of Virginia, which approved the protocol.
Sample characteristics are detailed in
Sample characteristics.
Montessori ( |
Control ( |
|
---|---|---|
Age at Time 1 | 41.31 months | 41.00 months |
Gender | 39 Male | 38 Male |
Household income | $73,208 | $68,914 |
Income range | $0–180,000 | $0–200,000 |
Mother education | 6.70 (1.30) | 6.64 (1.12) |
Father education | 6.37 (1.38) | 6.13 (1.23) |
Caucasian | 48% | 37% |
African–American | 17% | 15% |
Hispanic | 16% | 23% |
Asian | 3% | 4% |
Multi-ethnic | 16% | 20% |
All participants were recruited from Hartford, CT and its outlying suburbs by letters sent home from the school district office following a school choice lottery (see below) in each of 4 years spanning 2010–2013; each participating child was in the study for 3 years, so data collection spanned from fall 2010 through spring 2016. Letters were sent to parents of all 3-year-olds who had been entered in a lottery listing one of two public Montessori magnet schools as their first choice; the letters were accompanied by contact, demographic, and school information forms, a permission letter, and an envelope to return their information to the study coordinator. Parents were sent a $10 gift card as a thank you for returning the information forms. After spring tests each year, children were sent an age-appropriate book and parents were sent a $50 gift card.
The lottery was done by computer at the Connecticut State Department of Education’s Regional School Choice Office in Hartford, CT in May of each year. A child’s parent or guardian had submitted a lottery application during the period spanning October through February, selecting one of the two Montessori schools as their first of five school choices. The lottery selection was random except for neighborhood, sibling, and staff preferences. Staff children were disqualified from the study but 2 study children were admitted to a Montessori via the sibling preference; their siblings had presumably been admitted at random so the latent parent characteristics the lottery was intended to control for were still present. One control child had been admitted to Montessori but did not attend because the parents “did not like the neighborhood the school was in”; all other participants who gained admission to one of the two Montessori schools did become enrolled there. These two siblings and the admitted non-attender were assigned to the school program group they were actually in, but removing the two siblings and placing the cross-over child in the experimental group (“intent-to-treat”) had no meaningfully effect on results. For example, the ANCOVA on Time 4 academic achievement strengthens slightly when these changes are made, from
Forty-three control children attended the same schools for the duration of their time in the study; 26 made one school switch, and 1 switched schools twice. At the beginning of the study, the 71 control children were in 51 schools; most of those schools had 1 child, some had 2–3, and one had 4. Over the course of the entire study (6 school years), control children were at 71 different schools. (Children were tracked at the school, not the classroom level). Thirty of the 71 schools were publicly funded (15 magnet including for example Reggio, Arts, and Environmental Science schools; 8 conventional public schools; and 7 Head Start programs) and 41 were private schools. Thirty-two of the schools attended by control children were in Hartford city (including West Hartford, which is wealthier with an average household income of $120,000) and 39 were in the outlying suburbs. Public early childhood programs in Connecticut must (1) satisfy the NAEYC accreditation standards and (2) be a member of the state’s early childhood professional registry. Connecticut requires an Early Childhood Teaching Credential that entails either (1) being a graduate of an approved higher education program or (2) another higher education degree, teaching experience, and 12 credits in early childhood education.
One of the Montessori schools was the first public Montessori school in Connecticut, established in 1994. The other one opened in 2008. During the study years both Montessori schools were recognized by the Association Montessori Internationale (AMI) for their strict fidelity to original principles. One school had 5 classrooms and the other had 6 classrooms serving 27 three- to six-year-olds. One school also included students to 6th grade and the other to 8th grade; each had about 350 children in total. The teachers all had AMI training, for which a BA/BS degree is preferred but not required. Three of the teachers originally at one school had previously taught conventionally, and agreed to be retrained when the school converted to Montessori in 2008. There was some teacher turnover during the study but these changes were not tracked at either Montessori or conventional schools.
Over 4 years, 174 children were admitted to the study; 141 were retained in the final sample. Of these 141, 122 children were tested at all 4 time points, and 19 were tested at 3 time points. Of these 19, one joined the study at Time 2, 2 missed one test session, and 16 moved or crossed over between Time 3 and Time 4. 11 of these were in Montessori and 5 were control children. The control children who were lost had all moved; this lost subset of control children had performed significantly lower in academic achievement at earlier time points than the control children who did not move. The Montessori children who were lost at Time 4 did not significantly differ from those who remained in the study. Thus attrition patterns bias Time 4 results toward better outcomes for the control sample. For the variables reported here and the remaining children, 2.6% of data is missing due to experimenter error, child non-compliance, or interruptions in testing.
Of the 33 children who were admitted but excluded from the study, 23 children contributed insufficient data; 4 of these (2 Montessori) were lost between Times 1 and 2 and 19 (9 Montessori) were lost between Times 2 and 3. The children who were lost did not differ from other children in terms of parent education, parent income, ethnicity, or gender. The decision not to include these children was based on a preference for actual over imputed data. The other 10 excluded children (6 Montessori) had insufficient English (
All parents provided written informed consent. Testing was conducted one-on-one, usually in the child’s school, but in a few cases in a public library due to lack of school cooperation. Ten trained research assistants tested children over the course of the study (eight graduate students and two project coordinators). Tasks were administered in a fixed order chosen to vary formats for engaging children: Theory of Mind, Letter-Word, Alternate Uses, Design Copy, Puzzle Part 1, Math, Head Toes Knees Shoulders, Social Problem-Solving, Picture Vocabulary, Preference Questionnaire, Puzzle Part 2. Testing was done simultaneously at Montessori and control schools so that test time would not be confounded with school type.
Participants were administered the same tasks at all test points, except the Preferences Questionnaire and the Alternate Uses creativity task, which were added in the spring of 2011, so these tasks are missing at Time 1 from the 29 participants who enrolled in 2010.
On some tasks, having exactly the same items at different test points would threaten validity. For these tasks there were four sets of materials, administered on a rotating basis.
Children’s academic ability was assessed using the Woodcock–Johnson IIIR Tests of Achievement according to the instructions in the manual (
We used four tasks from the Theory of Mind Scale (
One object acquisition story from Rubin’s Social Problem-Solving Test - Revised was administered (
Executive Function was assessed with two tasks. For Head-Toes-Knees-Shoulders (
Second, the Design Copy subtest from the Visuospatial Processing section of the NEPSY-II was administered and scored according to the manual (
The puzzle task (modified from
A questionnaire was developed to assess children’s enjoyment of academic (school and reading) and leisure (media and play) tasks; four filler questions were included as well. There were four questions about each of the focal topics, and children rated their enjoyment by pointing to a sad, neutral, or happy face. These responses were coded as 0, 1, or 2, and added together. Since young children often give the highest possible ratings on such scales (
Alternative Uses was used to assess creativity (
Each intelligible response was scored as standard or non-standard. Categories were exclusive. For example, a standard use for a towel would be to wipe one’s body, and a non-standard use would be to place it over one’s head to pretend that one is a ghost. Analyses were conducted on the number of non-standard uses each child gave, collapsed across both items at each assessment. The actual range of responses was 0 to 5 total non-standard uses. Two coders independently coded a randomly selected subset of the data (
Some analyses reported here employed growth curve modeling, one of the most frequently used analytic techniques for longitudinal data analysis with repeated measures. Growth curve modeling can directly analyze intraindividual change over time and interindividual differences in intraindividual change (
A typical growth curve model can be expressed as
where
We use maximum likelihood estimation methods to fit the model. Missing values are believed to be missing completely at random (MCAR) or missing at random (MAR). Thus, Full Information Maximum Likelihood method (FIML) is applied to deal with missing data.
Data were not nested in control classrooms for the obvious reason that most control schools had only one child, and children’s classrooms and teachers were not tracked because they were not the focus of this study. Data were also not nested within Montessori classrooms, and the reason for this might be less obvious: Every year the 11 Montessori classrooms were differently constituted. First, peers changed: Always, at least 33% of children turned over as the oldest group of 9 moved on and a new group of 9 three-year-olds entered. In addition, several teachers and assistants turned over at some point during the study (although this was not closely tracked, at least three teachers at one school turned over), rendering different teacher experiences for each wave of children entering a given physical class (some had teacher A for 3 years, others for 2, others for 1, and others did not have teacher A at all). For this reason, treating children who entered a given classroom in 2010 and those who entered that classroom in 2013 as being in the same class (as a nested design would do) would not make sense; they had no overlap in peers, and many had different teachers as well. If we treated each entering year as different classrooms, we would have many tiny groups (1.6 children per nested group on average, given the average of 6.36 children per classroom entering over 4 years). Nesting Montessori children in classrooms therefore did not make sense. Analyses comparing results at the two Montessori schools revealed no school differences.
The groups were slightly (although not significantly) different in academic achievement at the first test point. Since the children were randomly assigned to Montessori or the waitlist, it seems most likely that these small differences were due to their respective school programs beginning to have an effect between the time of school entry and the initial test point (which was mid-December for some children, 3 months into the school year). This is further supported by lack of group differences in all the demographic variables.
Here we first explain how data were reduced, then discuss the results showing that Montessori preschool elevated performance overall for the whole sample. We next discuss results showing that Montessori equalized performance of subgroups by raising the typically lower-performing subgroups towards the level of the higher-performing subgroups. We end with a comparison of public Montessori with public and private non-Montessori schools.
The Woodcock-Johnson scores loaded on a single factor and were significantly intercorrelated within each time point (
Correlation Table for Academic Achievement, Theory of Mind, and Executive Function across four time points. These variables were selected because their interrelations are of significant interest in preschool research. In this graphic representation, all squares are red because all correlations were positive. The shading legend is on the right. Darker colors (as well as larger squares) represent stronger correlations.
Although equal at the start of school, the Montessori group advanced at a higher rate across the study years, as illustrated in
Academic achievement across preschool by school type. The figure shows significantly greater growth in academic achievement across preschool for children enrolled in Montessori preschool (dashed blue lines,
Although children’s scores were equal at the initial test, a linear growth curve model showed that Montessori children had a significantly steeper rate of growth across the preschool years, Δ
Children in the two samples were equivalent throughout the study with respect to their social problem-solving skills; the average number of justice-related responses ranged from 0.24 to 0.97 across the 4 time points. An ANCOVA on Time 4 Social Problem Solving controlling for Time 1 comparing Montessori and control samples was non-significant
Linear growth curve analyses did not indicate differences in the growth of executive function. An ANCOVA on Time 4 executive function controlling for Time 1 only showed a trend toward a difference, with Montessori children scoring more highly:
At the first two time points, there were no group differences: 37 of 70 Montessori (53%) and 35 of 71 control children (49%) chose to try a difficult puzzle again on one or both occasions (Fisher’s Exact test,
An ANOVA showed that the Montessori children were relatively more positive about school-related activities than were the control children,
Enjoyment of recreational
Children in the two samples were equivalent throughout the study with respect to their creativity; average non-standard uses scores ranged from 0.31 to 1.55 across the 4 time points. An ANCOVA on Time 4 Creativity controlling for Time 1 Creativity comparing Montessori and control samples was non-significant
We examined two sets of subgroups. First, we looked at the association of achievement with household income in Montessori vs. control schools. Because this achievement gap has been of considerable interest in the country historically, we present several analyses of this issue, before examining the influence of different levels of executive function in each sample.
Income is typically associated with school achievement. This was the case in the control sample, as shown in the right hand side of
Relation between academic achievement and household income in Montessori and control children at the end of the kindergarten year. The relation is significantly smaller in Montessori children (
How strong the gains in academic achievement were among just the lower income children is also of interest, because of the income achievement gap. Although the income range was very broad, there was not a sufficiently large subsample to only examine those living below the poverty line, so instead we examined the study subsample with a household income below the median split. For this lower income half of the sample (
Academic achievement across four time points by school condition and income group. Although equal to the lower income control children at Time 1, by Time 4 the lower income children in Montessori showed a strong positive trajectory towards closing the achievement gap with the higher income children in control and Montessori schools. Standard error bars are shown.
Furthermore, Montessori education greatly reduced the achievement gap across the preschool years. A series of four
Second, we examined the predictive power of executive function for achievement. For both Montessori and control children, higher executive function predicted academic achievement at Time 1 (the intercept). In the control sample, as expected from many studies, executive function also predicted the slope of academic achievement in the latent growth curve model, Δ
Because control children were at both private and publically funded schools, we examined how Montessori children compared to both groups on academic achievement, theory of mind, and executive function. Controlling for academic achievement at the first time point, there was a significant school type effect on academic achievement at the final time point,
Assisting young children’s development is an essential societal task; the human brain undergoes tremendous development in the early school years, setting in place patterns that predict life trajectories (
Taking advantage of a computerized random lottery for placement in two Montessori magnet preschools, this study compared 70 preschool-aged children who attended Montessori with 71 who did not. This is to our knowledge the first study spanning three years of Montessori education, and the second Montessori study to use a lottery-loser control design; the present study had a much larger sample size, and used new measures.
Montessori education elevated all children’s performance on several measures, and made the performance of groups that typically do less well more equal. First, academic performance of children in Montessori programs was significantly stronger over time. They performed slightly (but not significantly) better at the first time point, perhaps because children had on average almost 2 months of school program experience at the first test, with some children having a full 3.5 months. By the third and fourth time point, the differences in academic achievement were significant.
Furthermore, Montessori education made substantial headway in reducing the income gap in achievement across the preschool years. Whereas lower income control children were performing a full standard deviation lower than higher income control children by the end of preschool, the difference in income groups in Montessori was just a third of a standard deviation. Statistically, the lower income Montessori children did not differ from the higher income children in either school group by the fourth time point. In keeping with this, the income-achievement correlation was significantly smaller for children in Montessori than for children in the control group. This is a very important and impressive finding in our national search for ways to better help children born at an economic disadvantage.
Importantly, the higher achievement in Montessori was not at the expense of social skills or of liking school. Children who had by lottery ended up in Montessori programs performed better on tests of social cognition, were more mastery oriented, and expressed more liking of academic tasks relative to how much they liked recreational tasks. All these variables have predicted better outcomes in other studies, cited earlier. Montessori children fared equally well on tests of social problem solving and creativity, and had better executive function at age 4.
Finally, many studies have shown better academic and life outcomes for children with higher executive function or self-control. While for the control children in this study as well, executive function predicted academic achievement, this was not the case for children in Montessori. In Montessori classrooms, having lower or higher executive function did not matter for achievement; children with lower executive function performed as well as children with higher executive function in Montessori on academic achievement, which is impressive given that academic achievement in the Montessori sample was higher overall. Next we speculate on some possible reasons for these results, considering first intrinsic program differences in outcomes, followed by the possibility that Montessori teachers are superior.
Children in Montessori programs excelled in academic achievement. The Montessori materials and presentations are one possible reason. The materials capitalize on the embodiment of cognition, for example having children trace letters as they say the letter sounds, and match cards with words to small objects. Ample research suggests that this is a more effective way to learn than sitting and listening (
This study aligns with two prior studies in showing that children in authentic (in this case, AMI-recognized) Montessori environments perform better on theory of mind than other children (
Children in Montessori programs were more mastery oriented by ages 4 and 5 than were children in the control sample. One possible reason for this is the lack of extrinsic rewards in Montessori programs. The reward systems used in conventional school programs tend to lead to ability-oriented theories about oneself (
Although the children in this study all really liked recreational activities like watching television and movies and playing, children in Montessori showed relatively more liking of academic tasks like reading and getting lessons from a teacher. One possible reason for this is that children have choices about how they spent their time in Montessori; such choice is increasingly rare in preschool programs generally (
Unlike some other studies (
The finding concerning executive function and prediction of academic achievement is notable. Many studies have shown that executive function in the early school years predicts academic achievement (
One possible reason why executive function was not predictive of outcomes within the Montessori preschool program is that Montessori is a form of differentiated instruction. Children are not all treated alike; a child who needs more structure can be given that by the teacher. For example, a child who has not developed an ability to make constructive choices can be given limited, or even no choice, by the teacher, whereas a child who makes good choices (for example, chooses challenging work) is allowed to make their own choices. Closer examination of in-classroom processes, noting whether teachers do in fact scaffold lower executive function more effectively in Montessori programs, would shed light on this.
One might ask whether executive function near the time of school entry not predicting academic achievement is problematic. It does not seem so, since executive function still developed similarly in both groups and academic achievement was higher overall in the non-predictive group (Montessori).
In addition to intrinsic program differences, another possible reason for better Montessori outcomes is that Montessori teachers might be better teachers; if so, perhaps children in their classrooms would excel regardless of what educational program the teachers implemented. The teachers were not the focus of study here, but future research should consider this possibility. It is notable that at one of the two schools, three of six teachers had been teaching in a conventional way prior to 2008, and opted for retraining when the school adopted a Montessori program.
Considering the possibility that the study is revealing teacher rather than program effects, we note two points at which the Montessori teachers might have become better teachers: prior to their teacher training, or during (and as a result of) the teacher training.
First, one might ask whether the standards for entering a program to be a Montessori teacher are higher. Most of the Montessori teachers in this study trained at the AMI teacher training center in Hartford. Up to the time of this study, the training center courses were usually undersubscribed, so the center took virtually all applicants (Hall, personal communication, June, 2017). In addition, virtually all those who take the 9-month course are awarded a diploma. However, it is feasible that people who are attracted to Montessori teacher training interact differently with children, and this difference could be responsible for the results obtained. Other studies have shown non-trivial teacher effects at preschool. For example, a large study of prekindergarten classrooms in states that support pre-K (as does Connecticut) indicated two teacher variables that are most predictive of child achievement (
Second, the teacher training for Montessori might create better teachers. In terms of time and course intensity, the AMI training seems comparable to the training required for an early childhood teaching certificate. It involves 9 months of lectures and practice teaching, creation of a set of notes explaining Montessori theory and curriculum, and a final examination. The AMI “professors”—the people who teach the teacher-trainees—typically had at least 5 years as an AMI-certified classroom teacher followed by about 7 years of apprenticeship to another teacher trainer, so they are also highly trained. However, one difference to early childhood education is that in Montessori teacher training courses, one focuses on just one system and theory (
Another possibility, which also needs to be studied, is that Montessori teacher training changes teachers, perhaps by making them more sensitively responsive or higher in instructional support. If this is the case, then Montessori teachers are different but for a reason that is generic to Montessori education. Throughout Dr. Montessori’s books, a warm and loving attitude to children is expressed, and Montessori teachers are expected to come to embody this attitude (
Two children working with Montessori decimal materials, with which preschool children perform multiplication and division of 4-digit numbers. Photograph by Laura Joyce-Hubbard, provided by courtesy of Forest Bluff School.
Various means should be used in future studies to look at the degree to which teachers might be responsible for better outcomes in Montessori education. First, one could examine attitudes toward and interactions with children prior to, during, and following teacher education courses, comparing those in Montessori and conventional training, to see how each type of teacher training changes people. Second, measures of teacher–child interaction could be used in studies like this, and entered as separate predictors in regression models, to see whether teacher interaction style in Montessori loads as or more strongly on outcomes than it does in studies of conventional teachers, for example using the CLASS (
Even if Montessori teachers differ in some ways from other teachers that cause better child outcomes, the Montessori materials and the methods with which the materials are used probably also add value. Two studies speak to this issue, both capitalizing on the fact that many Montessori classrooms do not offer exclusively Montessori materials. In one study, among 14 Montessori classrooms, children advanced more across a school year in classrooms that offered only Montessori materials than in “Montessori” classrooms that mixed in conventional materials like commercial puzzles (
A major strength of this study is also a major limitation: It is based on a lottery for admission to two oversubscribed schools. Not all lottery entrants could be located (some had moved and left no forwarding address) and not all who were contacted agreed to enroll. School lottery entrants are not representative of all children, and oversubscribed schools differ from undersubscribed ones. In the real world, lottery designs are often the best available; longitudinal lottery studies are supreme. However, a lottery study is not as good as a true randomized control trial, where everyone is randomly assigned and is made to stay in their assigned group.
Another major strength that is also a limitation is that the study used high fidelity Montessori schools. Montessori outcomes appear to depend on the quality of the Montessori program (
Bearing these limitations in mind, the present study offers evidence that high fidelity Montessori preschool programs are more effective than other business-as-usual school programs at elevating the performance of all children, while also equalizing outcomes for subgroups of children who typically have worse outcomes. First, Montessori programs reduced the income achievement gap, raising achievement of lower income children well beyond the levels achieved by the lower income waitlisted controls. In addition, Montessori programs appeared to work as well for children who were lower in executive function at the outset as for children who were higher in executive function at the outset. Since preschool achievement predicts later achievement (
Widespread implementation of Montessori programs would be premature prior to further research to examine the external validity of this study. There are over 450 public schools in the United States that offer Montessori education (
The study was carried out in accordance with the recommendations in the guidelines for human research of the Institutional Review Board for the Social and Behavioral Sciences at the University of Virginia, which approved the study protocol. Parents or guardians provided written consent for all children’s participation in accordance with the Declaration of Helsinki.
AL conceived of and obtained funding for the study, arranged with the sites, submitted initial IRBs, chose stimuli, oversaw all aspects of running, led effort in writing and statistical analyses and submissions. MH arranged for and did data collection in final study year, entered and cleaned data, maintained family contacts, assisted with analyses and writing. ER arranged for and did data collection in 5th year, entered data and maintained family contacts for 4 years. XT conducted growth curve and bootstrapping analyses as well as conceptualization of data, assisted with manuscript. AH created procedure manuals and materials sets, and maintained family contacts and data base, trained and maintained contacts with on-site RAs, and arranged for data collection visits in first several years of study. PB supervised RAs on site in Hartford, stored material sets, facilitated local contacts, provided Hartford school information, and assisted with manuscript.
The following factor model was fitted separately at each time point:
Factor loadings and fit indices for academic achievement and executive function.
Time 1 | Time 2 | Time 3 | Time 4 | |
---|---|---|---|---|
Letter word | 0.531 | 0.541 | 0.647 | 0.682 |
Math | 0.945 | 0.906 | 0.785 | 0.789 |
Vocabulary | 0.629 | 0.602 | 0.560 | 0.530 |
Head toes | 0.182 | 0.639 | 0.531 | 0.612 |
Copy figures | 0.198 | 0.547 | 0.498 | 0.540 |
CFI | 0.998 | 0.993 | 0.966 | 0.976 |
RMSEA | 0.025 | 0.043 | 0.091 | 0.077 |
SRMR | 0.030 | 0.029 | 0.034 | 0.031 |
A further analysis was done to determine fit with factors constrained to be equal; these results are shown in
Factor loadings and fit indices for academic achievement and executive function: constrained.
Time 1 | Time 2 | Time 3 | Time 4 | |
---|---|---|---|---|
Letter word | 0.726 | 0.700 | 0.663 | 0.678 |
Math | 0.726 | 0.700 | 0.663 | 0.678 |
Vocabulary | 0.726 | 0.700 | 0.663 | 0.678 |
Head toes | 0.195 | 0.588 | 0.512 | 0.575 |
Copy figures | 0.195 | 0.588 | 0.512 | 0.575 |
CFI | 0.916 | 0.931 | 0.960 | 0.962 |
RMSEA | 0.111 | 0.107 | 0.075 | 0.073 |
SRMR | 0.072 | 0.071 | 0.050 | 0.058 |
In this analysis, for Time 1, when factors are constrained to be equal, model fit is more than adequate by two indices (CFI and SRMR) but by the RMSEA model fit is not good initially, when children are younger and there is more error (some very young children might not understand test instructions, for example); it becomes acceptable by Times 3 and 4.
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
The authors thank the children, parents, and school administrators as well as the Regional School Choice Office in Hartford for their participation; Tim Nee for facilitating the project; and Hedy L. Azarhooshang, Samantha Cusak, Theresa Heinz, Erin Kenney, Sheila Morely, Ariel Rodriguez, Carmen Trainer, and Ashley Wodzicki for collecting data.