Our School

Our Director

If Diane Sartor could be summed up in one word, “passion” would be the best candidate. Energetic and driven, Diane has a tremendous enthusiasm for language, teaching, and life, a passion which she has channeled into her more than 30 years of mentoring students.

“Today’s students are challenged to learn faster and absorb vast amounts of information to keep up with the demands of our rapidly changing world. As educators, we have a responsibility to guide our students to embrace challenge, create reachable goals, and provide them with the skills they need to succeed, not just on their road to college, but in life as well.”

Diane Sartor



Research and



At the heart of Keystone Education is the research and development that goes into crafting our unique lesson plans and original standardized test content. Under the guidance of Director Diane Sartor, administrative policies are set, teachers are trained, and research is conducted into the latest developments in standardized tests and educational trends.




Dedicated Curriculum Team

Using dozens of real tests as a foundation, our in-house team of curriculum experts creates challenging original materials for use in the classroom. From writing and reading to mathematics and grammar, we devise the best exercises to test and teach fundamental test-taking skills and strategies to prepare for the common core and other standardized tests.

Classes for Every Level

While some test prep companies may focus only on high school students, we believe in preparing students at every level. Good study habits and fundamental skills need to be learned in grade school or middle school for students to achieve the best results. We offer classes of various levels based on age and ability, including classes for those who are just beginning to learn English.

Cutting-Edge Technology

All of our classrooms are equipped with smart-board technology, helping teachers bring the lessons to life and increasing interactivity within the class. Students respond well to the twenty-first century approach and are more eager to engage with their exercises.

Innovative approach

Our teachers inject their unique characters into each class, teaching lessons in a variety of ways that keep the class active and inspired. From the competitive strategies of gamification to brain-enhancing projects like our Memory-Flash Vocab system, we are always seeking new and better ways to educate the next generation of students.

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Contact Us

Tel: 909-860-9345

Email: office@keystone-education.com


660 N. Diamond Bar Blvd. #168 Diamond Bar, CA 91765

© Copyright 2020 by Keystone Education