PTC-SC Officers and Board of Directors
Celeste Arellano
Celeste Arellano is a Senior Human Resources Analyst with the City of Ontario. She began her public-sector human resources career in 2018, previously serving in public school districts and has experience in recruitment and selection, classification and compensation, test development, and other personnel functions.
Celeste holds a Master of Public Administration and a Graduate Certificate in Public Sector Human Resources Management from Penn State University and is PSHRA-CP certified. She has served on the PTC-SC Executive Board since 2022 as Vice President of Communications, President-Elect, and currently as the 2026 President.
Vacant
Dr. Frank Olmos
Dr. Frank Olmos, Ed.D., serves as the Executive Director of Classified Personnel and the Personnel Commission at Bellflower Unified School District, where he leads recruitment, classification, examination, and merit system administration for the district’s classified workforce. He brings more than twenty years of experience in California Merit System human resources, with prior service at the Los Angeles County Office of Education and Montebello Unified School District.
Beyond his district role, Dr. Olmos is the President of DFO HR Consulting, an Adjunct Professor of Statistics at California State University, Los Angeles, and the author of Smells Like A.I. Spirit. He developed the CHATPROMPT prompt engineering framework and speaks regularly on the responsible use of AI in personnel work. In 2024, he received the Stephen E. Bemis Memorial Award for his contributions to the field.
A Past President of PTC-SC, Dr. Olmos continues to support the organization’s mission by contributing his expertise in personnel selection and merit system practice.
Dr. Vina Napoles
Dr. Vina Napoles holds a PhD in Business Psychology with a specialization in Industrial-Organizational Psychology and serves as a Senior Personnel Research Analyst with the City of Los Angeles Personnel Department, where she supports both the Recruitment and Examination Sections within the Personnel Selection Division.
Additionally, she contributes to the department’s Research & Development and Employee Engagement initiatives, supporting efforts focused on organizational effectiveness, workforce development, employee experience, innovation, and continuous improvement.
Drawing on her expertise, Dr. Napoles is passionate about helping organizations strengthen member engagement, foster meaningful professional connections, and create positive workplace experiences that support both individual and organizational success.
Dr. James Hsiao
Dr. James Hsiao is an Industrial-Organizational Psychologist with over a decade of expertise developing, validating, and implementing hiring assessment systems across government agencies and private industries. As Co-Founder and Head of the Research and Development team for the City of Los Angeles, he applies I-O psychology to boost organizational efficiency. His multifaceted leadership role spans applied research, strategic collaboration, publishing the City’s R&D Newsletter, and studying emerging trends like employee AI readiness.
Holding a Master’s degree in Experimental Psychology, Dr. Hsiao possesses a deep understanding of social psychology, particularly regarding prejudice and bias. This foundation informs his applied expertise and numerous publications addressing testing fairness, workforce diversity, and predictive validity. His technical skill set covers the full lifecycle of assessment development, from rigorous job analyses to situational judgment tests and performance-based exams. Using advanced statistical methodologies, he ensures psychometric precision and legal defensibility for recruitment at all management levels.
As an active contributor to the Personnel Testing Council of Southern California (PTC-SC), Dr. Hsiao collaborates with major municipalities to tackle public sector hiring challenges and coordinate expert conference panels. He is widely recognized for seamlessly merging empirical research with practical applications to design equitable, highly effective assessment systems.
Shawn Toyohara
Currently serving in his second year as Vice President, Programs on the PTC-SC Board, Shawn has been an active member of PTC-SC since 2020 and has regularly attended PTC conferences and events to stay engaged with our personnel testing community.
Professionally, Shawn is an HR Analyst with the Personnel Commission office at the Los Angeles County Office of Education (LACOE). He began his career with LACOE as an intern in September 2019 before transitioning into his current role. In this position, Shawn regularly leads recruitment and classification projects and has served as a core team member on the development of RaterView, an evaluation application designed to streamline the rater experience.
He earned his Master of Science in Industrial and Organizational Psychology (MSIO) from California State University, Long Beach in May 2020. Through his work at LACOE and his role on the PTC-SC Board, Shawn remains focused on supporting public sector personnel testing practices and delivering meaningful events and luncheons for members.
Jonnell Sanchez
Jonnell Sanchez is PTC-SC Treasurer and has held multiple roles on PTC-SC since 2020. She is a Personnel Director who brings over 10 years of private sector experience in client relations as well as determining minimum qualifications, developing job descriptions, and hiring exceptional candidates.
She has served the Bassett Unified School District community for eight years in the Personnel Commission. She received her bachelor’s degree in Communications from California State University, Fullerton and enjoys going to the dog beach with her fur baby Mochi in her free time.
Melissa Venegas
Melissa is a Human Resources Analyst with the Los Angeles County Office of Education (LACOE). She has a combined six years of HR experience beginning with the Los Angeles Unified School District in their Personnel Commission’s Classification and Compensation Branch. She now leads recruitments and classification studies at LACOE.
Melissa joined PTC-SC in 2025 as the Co-Chair Vice President of Programs and now serves as the PTC-SC Secretary. Outside of work, she enjoys sci-fi, horror, and romance media and going to as many concerts as she can.
Alexis Nakamura
Alexis is a Sr. Personnel Analyst II with the City of Los Angeles Personnel Department and currently manages a team of analysts responsible for creating and administering civil service exams for the City. She has 13 years of experience in public sector selection, including working with high visibility client departments such as LAFD, LAPD, and the Department of Water and Power.
She has attended PTC-SC events for several years and has served on the PTC-SC Board since 2019 in different roles, including as President in 2023. Outside of work, she enjoys reading romantasy and saving dinner recipes on social media that she never actually ends up cooking.
Amy Tompkins
Amy is currently a Selection Analyst with CODESP, where she creates and edits selection materials ranging from multiple-choice test items to writing and performance assessments.
Her past experience includes IT Liaison responsibilities for managing IT projects from the user side in collaboration with the IT department, maintaining web content, and providing statewide training on IT systems for HR users.
Clare Caldera
Clare Caldera is a Human Resources Analyst with the City of Santa Monica, where she manages recruitment and selection processes, conducts classification and compensation studies, and supports a variety of strategic human resources initiatives.
She has worked in public sector human resources since 2014 and enjoys connecting with fellow HR professionals to share best practices in public sector recruitment and selection. Clare has been involved with PTC-SC since 2014 and served as President in 2021.
Outside of work, you’ll find her doing CrossFit, teaching yoga, traveling the world, or cleaning up after her two rescue cats.
Luke Poulter
Luke Poulter is a Personnel Research Analyst with the City of Los Angeles. In his current role, Luke conducts job analysis, develops and administers employment examinations, performs statistical and data analyses, and prepares technical and narrative reports.
He also serves as the Interview Specialist Coordinator, overseeing a team of 17 part-time, as-needed Interview Specialists and supporting the consistent, efficient, and high-quality administration of structured interviews and assessment processes.
Before joining the City of Los Angeles, Luke served as a Human Resources Specialist with the Los Angeles Unified School District. Luke holds a Master’s degree in Industrial and Organizational Psychology from California State University, San Bernardino, and a Bachelor’s degree in Psychology from Southern Utah University.
Luke also serves as a Director At Large for the Personnel Testing Council of Southern California and previously served as Secretary and Vice President of Conferences, supporting professional development and collaboration within the personnel assessment community.
