Sean Hamer, Ed.D., Head of School

Sean believes education is a process that empowers individuals with the resources to experience a life of understanding, promise, and options. Sean comes to AVS after serving as the Head of Middle School at Germantown Friends School in Philadelphia. Previously, he served as Head of Middle School at Friends Academy in North Dartmouth, Massachusetts and as Dean of Faculty at Breakthrough Collaborative, a non-profit in Philadelphia which provides disadvantaged students from under-resourced schools with the support they need to academically succeed. Sean’s passion for the natural and physical sciences are rooted in his elementary experiences in Montessori school, sleep-away summer camps, computer programming experiences in middle school, and concurrent formative experiences at the three-summer (MS)2 program at Phillips Andover Academy. These experiences directed Sean on a path toward engineering, however, he discovered a passion for working with children during his college study as an engineering student. He has spent significant time in the New England area as a teacher at the elementary and middle school levels at Shady Hill School, the Graham and Parks Public School, Charles River School, and the Gordon School as well as an adjunct professor of math and math education. Sean was the Technology Collaborator for the middle school and served as a facilitator for the Gordon School’s Multicultural Institute. Sean values a school culture where the community of learners, including the teachers, feel safe to take risks. He also believes in sharing in the fun in students’ lives and has supported students’ extracurricular pursuits as a coach for basketball, field hockey, softball, and a club leader for chess, robotics, and martial arts. Sean enjoys time with his family and has interests in personal development, entrepreneurship, hot yoga, martial arts, film, cooking, and writing.


  • B.A., Human Services; Minor in Chemistry - University of Massachusetts

  • M.Ed., Mathematics and Science Education - Lesley University, Massachusetts

  • Ed.M., Education Leadership - Columbia University - Teachers College

  • Ed.D., Policy, Planning, and Leadership; K-12 Administration and Supervision - College of William and Mary, Virginia

Katie Gibbons, Head of Lower School

Approaching education with great purpose and passion, Katie has devoted the past eighteen years of her career to devising the best tools to unlock students’ intellectual, creative, and emotional potential. Specializing in learner-centric, inquiry-driven, differentiated, and project-based curriculum, Katie makes learning come alive so that it becomes a transformative experience. For more than ten years, she has taught K-5 classes in a variety of educational settings — an urban charter school in Pennsylvania, a public school in a rural Yupik village in Alaska, and private schools in the San Francisco Bay Area. For five years, Katie has served as an administrator at two K-8 independent schools that she has helped to establish in the Bay Area: She was the Founding Teacher and Associate Head of School at Synapse School in Menlo Park and the Founding Head of School at AltSchool, Fort Mason campus. Committed to creating a safe and innovative learning environment for students and faculty, she co-authored the book, "TRUST or DOUBT: Essential Strategies to Co-Create Thriving Teaching Teams." 

  • ​B.S., Elementary Education – Elizabethtown College

  • ​M.A., Educational Leadership and Administrative Services - Mills College

  • Certified as Advanced Trainer of Social and Emotional Learning – Six Seconds, The Emotional Intelligence Network

  • Credentials: Administrative Services - California
    Multiple-Subject Teaching - California, Alaska, Pennsylvania 

Liz Davis, Head of Middle School

Most recently, Liz served as Assistant Head of School at Synapse School in Menlo Park, a project based, K-8 independent school with a strong focus in innovation and social-emotional learning. Her previous administrative roles include Director of Curriculum at Keys School in Palo Alto and Director of Academic Technology at Belmont Hill School in Belmont, MA. She has taught middle school during most of her 25 years in education, starting out as sixth grade math and science teacher. In 2013, she was selected as an NAIS Teacher of the Future and as a member of the NAIS Innovation Task Force. She is excited to work with the AVS community to continue to build a strong mission-driven culture based on shared values.


  • B.A., Psychology - Dartmouth College

  • M.A.T., Elementary Education - Simmons College

  • Credentials: Elementary Education K-6 – Massachusetts

  • Technology Integration Specialist K-12 - Massachusetts

  • Ed.D. Candidate - Vanderbilt University (Online)

Mishel Gantz, ​Director of Enrollment and Admissions

Mishel joins Alta Vista School with more than twenty-five years of experience working in schools. Mishel is a seasoned teacher who has taught all ages, from junior kindergarten through twelfth grade. For the last eleven years, Mishel has focused her abilities on admissions. Most recently, Mishel served as the Director of Enrollment at Synapse School, a K-8 project-based, SEL focused program in Menlo Park. Previously, she was the Chief Experience Officer at Watershed School, a forward-thinking, grades 6-12 independent school in Boulder, Colorado. Mishel has a passion for creating customer-centric family experiences. Mishel holds a B.A. in Psychology and has a range of certifications and training in internal family systems, grief counseling, education, and enrollment. Most importantly, Mishel is a proud parent of two grown children.

  • B.A., Psychology - University of South Florida

  • Praxis Certified K-8 Educator - Colorado

  • Certificate, Admission & Enrollment Management

Krissi Lewis, Associate Director of Enrollment and Admissions

Krissi Lewis has over 15 years of professional experience working with young children in a variety of settings. Krissi is also a facilitator for parenting groups throughout the city. Krissi brings a wealth of knowledge and insight from her diverse professional background, as well as her own experiences as a parent, and enjoys supporting other parents through this amazing journey.

Yukiko Meadows, ​Director of Development

Yukiko Meadows has spent her life attending, working and parenting in independent schools in the Bay Area. For the past twenty years, she has worked in the Development field focusing on educational fundraising, marketing and communications. She is deeply committed to creating community through engagement of parents, friends and staff. A native San Franciscan, Yukiko lives in the city with her husband and children and has been actively involved with many non-profit groups. She looks forward to be an active member of the AVS community and getting to know all our families. 


  • B.S., Management, USF

  • CFRE, Certified Fund Raising Executive

Michael Fariss, ​Director of Technology

Michael loves helping the faculty do what they do best: Giving the next generation of young minds what they need to handle the wonders of the future. He has been delivering technology to education for over two decades, including giving two schools their first Internet connections. He has worked at several local schools, including Sacred Heart, Woodside Priory School, and St. Elizabeth Seaton. At the Woodside Priory School, he ran the IT department and created both databases and network infrastructure that was a few years ahead of the pack. He cares about delivering compassionate service, educating the next generation, and making systems simple to use.


In addition to his time in education, he has experience with databases, networking, and cloud infrastructure from his time at Hewlett Packard, Metro Newspapers, and other database firms. Michael also enjoys the outdoors with a good hike, skiing, and most anything that pedals, drives or moves fast.

  • B.S., Software Engineering - San Jose State University

  • M.B.A. - Argosy University

  • Management - Berkeley Extension

Kory Orlanski, School Counselor

Kory has been dedicated to preserving the health and wellness of adults, children, adolescents, and their families in San Francisco for the last 15 years. She has skillfully created a safe and trusting environment in schools, agencies, and currently in her private practice. Through her work with clients individually, in groups, and facilitating workshops, Kory has found presence, active listening, creativity, humor, and compassion to inspire one’s growth and resilience. She is thrilled to bring her passion, knowledge, and experience to the Alta Vista School.

  • B.A., Psychology with Honors - California State University, Northridge

  • ​M.A., Clinical Psychology with emphasis on Marriage and Family - Pepperdine University

Toni Setteducato, Middle School Dean of Students

After serving as a founding AVS middle school science teacher for the past three years, Toni is thrilled to transition into an administrative role where she will fully support all middle school students. While working as a middle school student advisor, Toni supported students with their diverse academic, social, and emotional needs and found her passion for directly guiding and advocating for all learners. Having worked at AVS for the past three years, she has formed relationships with, intimately knows, and deeply cares for AVS students and their families.  Toni looks forward to ensuring that all students flourish within and outside our community, as she guides students in making thoughtful academic choices that will further their success such as with the high school selection process. As a lead facilitator on various student support teams, Toni has worked closely with parents, teachers, and learning specialists to provide academic guidance and to create various learning and social support structures for students with diverse learning profiles. An educator for 20 years, she understands the academic and emotional support that students need to make significant progress and thrive in middle school grades. When not surrounded by the chaos and joy of middle school, Toni is out and about exploring all of the city’s urban and natural splendor. She has a deep love of weekend hikes, her canine companion Hailey the Pupfessor, soccer, college basketball, and yoga.

  • B.A., Psychology - Villanova University

  • M.A., Earth and Environmental Studies, concentration in Middle School Earth and Environmental Science - Montclair State University

  • Credentials: Teaching Elementary Education K-5 – New Jersey

  • Middle School Science 5-8 – New Jersey

Bonnie Hallman, Learning Specialist

Bonnie arrived at Alta Vista’s Lower School in 2017, after moving from the east coast. Her curiosity and care for the individuality of student learning needs was ignited when she first served as a camp counselor at a summer program for students with language-based differences. Bonnie recalls engaging with a persistent young reader who accessed language in an incredibly unique way, and she knew that she wanted to be immersed in the world of such learners from thereon out. Bonnie holds a bachelor’s degree in special education and a master’s degree in language and literacy instruction, both of which have furthered her understanding of diverse learning needs inside and outside of the classroom. Bonnie is also Orton-Gillingham trained and certified, and she uses this multisensory approach to language to design personalized instruction for a wide range of learners. After two years of teaching second grade at the Lower School, Bonnie is excited to continue to connect with and support learners and teachers in differentiated ways. When away from school, Bonnie can be found drinking coffee and reading outdoors in Potrero Hill. Bonnie’s passions also include eating burritos in the Mission District, being active outdoors with friends, petting cats, and visiting friends and family.  

  • B.S., Special Education - Boston University  

  • M. Ed., Language and Literacy  - Harvard University

  • Credentials: Moderate Disabilities K-8 - Massachusetts

  • Reading Specialist K-8 - Massachusetts

  • Education Specialist Instruction - California

  • Orton-Gillingham Trained Instructor

Paul McNees, Literacy Specialist

Paul entered his career as an educator at a Montessori school in 1991. As a public school kid in Missouri, he had never encountered such a brilliant and unique method of teaching young children. Independence and discovery were the names of the game. Paul found that he had a knack for creating manipulatives for all facets of the curriculum and scaffolding skills or concepts so that all students could succeed. Understanding these techniques were useful for teaching children who had diverse learning styles. Constructivist philosophy, the use of teacher-made materials, and creating lessons geared to the individual student inspired him to move into educational therapy. 


Paul is thrilled to join the Alta Vista family as the Literacy Specialist where he is among a vibrant, creative, and inclusive community of people who are dedicating their lives to the well-being of children. His love of the written word and reading go back as far as he can remember. He was one of those students who was fascinated by diagramming sentences and seeing how language could be deconstructed and then rebuilt into beautiful cascading geometric forms. As he grew from high school to college and later to graduate school, he was struck by how the rhythm and melody of the written word could play into the imagery that the author was trying to create. Paul uses all of these sensory tools in his teaching: the patterns, the rhythm, the love of words, all the ways to play with language, and beginning to find one's own voice.


  • B.A., Audio/Visual Art - Webster University

  • M.A., Philosophy and Religion - California Institute of Integral Studies

  • M.A., Educational Therapy - Holy Names University

  • Credential in Montessori Education (ages 6 - 12)

  • Credential in Orff Schulwerk Music for Children

  • Orton Gillingham Trained Instructor

Rhiana Maidenberg, Math Coach

Rhiana has been teaching mathematics for the past 18 years. Her teaching career began as a middle school math educator in Washington, D.C., followed by three years of teaching high school math at The American School in Tokyo, Japan. After her children were born, she began to study how the elementary-aged child learns problem-solving and number sense. Rhiana has spent the past five years as the Math Enrichment Specialist for Sunnyside Elementary School.


As a math coach, Rhiana’s primary goal is to help students find beauty and meaning in mathematics, not only in a school environment, but at home and in the world. When she is not working with students and teachers, Rhiana enjoys hiking with her dog, Luna, and traveling with her husband and daughters, Elana and Maisy.

  • ​B.A., Mathematics - Washington University, St. Louis, Missouri

  • M.S., Secondary Math Education - American University, Washington, D.C.

Rebecca Sacks, Technology Integration Coach

Rebecca Sacks has always felt most comfortable living a diverse professional life -- from singing opera professionally to consulting as a public health biostatistician to working in product management with a machine learning startup in Venice Beach. She strives to bring this diversity of experience and excitement for the unknown to her role as Technology Integration Coach at Alta Vista School. She hopes to help students, families, and faculty navigate the challenges brought on by the COVID-19 pandemic by making our educational technologies accessible, fun to use, and easy to understand. She is passionate about the role of design in forming a person’s experience with technology, and is excited to put that to work through the development of new tools and systems. When she is not working, Rebecca loves to hike, play incredibly nerdy board games, and spend time with her beloved cat.

  • B.A., Music; Minor in Psychology - Stanford University

  • M.P.H., Epidemiology and Biostatistics - Oregon Health and Sciences University

  • M.M., Opera Performance - University of Georgia

Penny Pruzan, Business Manager

​Growing-up, Penny has always had an affinity for numbers. Realizing accounting as her career, she has garnered invaluable experiences with corporate, private, and non-profit organizations. Her personal interests include cooking, hiking, gardening, and good company. It is her pleasure to serve the Alta Vista Community.

  • B.A., Accounting - CUNY

Jenny Sommer, Lower School Front Office Manager and Executive Assistant to the Head of School

Jenny Sommer is a Bay Area native with a huge passion for photography, film, and helping others. She has been working in Office Administration and Office Management for the last 9 years and truly loves the hustle and bustle of working in a busy office. After graduating from John Swett High School in 2004, she pursued her passion for photography and film. In 2009, she graduated from Berkeley Digital Film Institute and has been freelancing as a photographer and filmmaker for the last ten years. At the lower school, she hopes to inspire AVS students to pursue their passions, think creatively, and always know there is a reason to smile. 

Patrick Jones, Middle School Front Desk Manager

Patrick is a fourth generation Californian and a lifelong lover of the arts and the outdoors. He has a background in acting and illustration and has worked professionally as an actor and a drama educator throughout the country. He also happens to be married to Ms. Katie, the middle school drama instructor. Patrick and Katie are parents to a dog, cat, and a fish -- which lives at the front desk. In his spare time, he loves to skateboard, swim, read, and camp. Patrick is grateful to be a part of the support team at AVS Middle School.

  • B.A., Visual Art - Humboldt State University

  • M.F.A., Acting - Case Western Reserve University & Cleveland Play House

Priscilla Morales, Middle School Front Desk and After School Care

Priscilla is a San Francisco native with a passion for traveling, movies, and cooking. She has worked with children in a variety of roles at different schools in the Bay Area, including after-school and summer programs. Priscilla graduated from San Francisco State University in 2018. She is thrilled to be a part of the Alta Vista Middle School team. 


  • B.A., Liberal Studies, San Francisco State University

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Administration and Support Team

©2020 Alta Vista School
 for curious young minds |

Lower School Campus:

450 Somerset Street | San Francisco, CA 94134 | ​Tel: 415-467-3700 

Middle School Campus:

2558 Mission Street | San Francisco, CA 94110 | Tel: 415-510-8492