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Rochester Central Lutheran School


Two students discussing in class
Robin Kaufmann


What matters most in the first years of school?

It’s one of the proverbial million-dollar questions. The stakes are high––our children, our workforce, our society. At the beginning of a lifetime of learning and labor, the first years of school are the foundation of all that will follow them. Shouldn’t we know the answer to this question?

Class Size Matters

It turns out, we do.

Students working at desks

While there are a few variables that impact academic performance and adult outcomes, it long has been hypothesized that class size is a significant factor in producing desirable outcomes––high test scores and college entrance rates, in particular. According to one literature review, “[v]olumes of research have looked at the relationship between class size and student performance in nonexperimental settings,” but Project STAR (Student/Teacher Achievement Ratio)––“a large-scale randomized trial of reduced class sizes in kindergarten through the third grade”––was an important controlled inquiry into the matter. A state-funded investigation, Project STAR took place in 1985-89 in nine Tennessee public schools and included 11,600 students and 1,330 teachers. After randomly placing students in small or regular K-3 classrooms, researchers observed statistically significant gains on a standardized assessment for children placed in a classroom with 13-17 students. This positive impact on test scores for small class sizes in K-3 persisted all the way through 8th grade, and researchers also note that small-class students were more likely to take college entrance exams, indicating a higher rate of college-bound students from small classes. Altogether, Project STAR has provided policy makers with compelling evidence that small class sizes in the first years of education––Kindergarten through 3rd grade––do benefit students, not just in those early grades, but years later, as well. “Overall,” writes researcher Diane Schanzenbach (2006), “Project STAR indicates that reducing class size is a reasonable economic investment. [. . .] The overall benefits outweigh the costs.”

Teacher and Class Quality Matter

But that’s not all. While initial analyses of Project STAR data isolated the class-size variable, later analyses attempted to isolate other variables––“teacher quality” and “class effects,” the admittedly imprecise variable that is really the milieu of teachers, peers, and other attributes of a classroom. In a long-term, ambitious attempt to provide “a unified evaluation of several outcomes, including the first analysis of [adult] earnings,” one team of investigators (Chetty, et al., 2011) considered: “do classroom environments that raise test scores––such as smaller classes and better teachers––cause analogous improvements in adult outcomes?”

Indeed, they do. Class size and quality matter. Kindergarten “class quality” has “significant impacts on both test scores and [later] earnings,” and data reveals similar findings for grades 1-3. This led these researchers to conclude that a “better classroom environment from ages 5-8 can have substantial long-term benefits.” Consider some of these benefits and the implications of them:

1.  College Attendance  ·  “Students assigned to small classes [in grades K-3] are 1.8 percentage points more likely to be enrolled in college at age 20.”

2.  Adult Outcomes  ·   “Students in small classes [. . .] exhibit statistically significant improvements on a summary index of [adult] outcomes” including home ownership, 401(k) savings, mobility rates, college graduation, and marital status.

3.  Non-cognitive Skills  ·   “Kindergarten class quality has significant impacts on non-cognitive measures in 4th and 8th grade such as effort, initiative, and lack of disruptive behavior.” This is a finding that researchers use to hypothesize that non-cognitive skills gained in the first years of school have returns in the labor market, something other social science researchers have considered in detail.

Class Size and Teacher Quality at RCLS

As a private school, RCLS can operate, to some degree, outside of the constraints of public funding, so we can be committed to keeping class sizes low and teacher quality high.

Teacher helps student read

“The single most important factor in a classroom is the teacher,” insists Mrs. Lagerwaard, RCLS’s principal. While RCLS devotes considerable resources to curriculum and programming, Mrs. Lagerwaard explains that highly trained, committed teachers are the school’s highest academic priority. After all, a curriculum and the materials that support it are only as good as the teachers who implement them. “I’ve worked in a number of educational contexts, but I have never worked with a more committed, more talented group of educators,” Mrs. Lagerwaard says. “Day after day, week after week, RCLS teachers go the extra mile for individual students.”

Still, Mrs. Lagerwaard notes that even the best teachers could only do so much in a large class. “You cannot take even a great teacher and put her in a class of 25 or more young students and expect her to be able to adequately nurture the academic, social, emotional, and spiritual needs of that many students. That’s why we are committed to keeping class sizes small. Currently, our average K-5 class is just 16 students.” Mrs. Lagerwaard is especially mindful of Kindergarten and 1st grade, where attention spans can be short and students often demand individual attention as they learn to learn. In these grades, classes do not have very many students before a teaching assistant is assigned to the class. In Kindergarten this year, for example, each of the classrooms of 17 students is supported by an experienced teaching assistant in addition to the class’s certified teacher during core academic portions of the day.

Current kindergarten parent, Mrs. Joanie Lande, has experienced this priority of class size and teacher quality at RCLS.

“After seeing our son, Logan, grow and learn at home and in preschool, we found out very quickly that he was rather bright, a fast learner, and had A LOT of energy. We were worried that, in a public school setting, he would get in trouble frequently if his mind wasn't stimulated enough, and if the classes were too large that he would be easily distracted [. . .]. We had heard RCLS was a small, family-like school that had GREAT teachers.

[. . .] Honestly, RCLS has so far exceeded my expectations. Logan is reading and writing, he has made new friends, he shares his stories about Jesus and other Bible lessons with us on a regular basis. I am impressed that he is comprehending so much at one time, and I can tell that he feels safe in his classroom and other school environments. I am impressed that the kindergartners are learning such advanced reading and writing skills [. . .]. 

He comes home every day with a smile on his face. [His teacher] is AMAZING! [. . .] She even called me one Monday morning when Logan was having a hard time accepting the school day ahead of him, and together we were able to talk him through it. She is ever-so-caring, and has many, many tricks up her sleeve to keep the students on-track and making progress. I am so thankful that we found a school right off the bat that is caring for my son's education AND his well-being. To me, that in itself is the foundation for the rest of Logan's school years. [. . .]”

Empirically, intuitively, and experientially, we know that class size and quality matter. RCLS is committed to what matters. Grace. Faith. Learning for Life. Class size and quality are just the beginning.


Want to learn more about how your child might benefit in a small class with high-quality teachers and peers? Visit RCLS at an upcoming Welcome Event or contact us to schedule a visit. We want to welcome you!

Welcome Events Information


If you'd like to learn more about Project STAR for yourself, try these articles/episodes:

Chetty, R., et al. (2011). How does your kindergarten classroom affect your earnings? Evidence from Project Star. Retrieved from

Schanzenbach, D. (2006). What Have Researchers Learned from Project STAR? Brookings Papers on Education Policy, (9), 205-228. Retrieved from

Vedantam, S., Cohen, R. & Boyle, T. (2019, Dec. 9). Zipcode Destiny: The Persistent Power of Place and Education. Hidden Brain. Podcast retrieved from