Meet the IAP2 USA Trainers!

 Cassie Hemphill  Kimberly Horndeski Heather Imboden
 Penny Mabie  Cathy SmithJustin Schneider
 Craddock Stropes  Doug Zenn 


Cassie Hemphill


Cassie Hemphill has more than 25 years of experience in public participation and 15 years designing and delivering training. Her courses emphasize transferable, applied skills participants use to become more effective in their work and personal lives and improve the world around them. Cassie’s Ph.D. research explored public/private collaboration in environmental management. Her M.A. research analyzed decision-makers' openness to public input. She has a Graduate Certificate in Conflict Resolution and is an IAP2 USA Certified Public Participation Practitioner (CP3), a Certified Mediator (CM), and a Certified Virtual Facilitator (CVF).



Kimberly Horndeski

Kimberly Horndeski is a certified mediator, facilitator, and the Executive Director of Community Consulting LLC. Her work focuses on transforming conflict into successful strategies for the future. She has led multiple state, national, and international working groups to overcome challenges and reach agreement. Her projects include bottom-up approaches, such as establishing a coalition with fundamentally conflicting interests to collaboratively negotiate agreement on a $2.5 billion dollar component of the Bipartisan Infrastructure Bill, and top-down approaches, such as assisting the U.S. Fish and Wildlife Service to incorporate nationwide stakeholder values into the decision-making process for federally-listed threatened and endangered species. Kimberly knows it is not information alone that produces positive outcomes or reduces conflict. It is the ability to engage key stakeholders and effectively design, plan, and implement an engagement process that results in creative and lasting solutions for the future. 

Currently, Kimberly serves on the USA Board of the International Association of Public Participation, the Leadership Council for the Association for Conflict Resolution’s Environment and Public Policy Section, and is a Professor of Practice on collaboration and communication for Virginia Tech University. 

What did the IAP2 Licensing Process say about Kimberly’s trainings --- 

Kimberly has an infectious, enthusiastic, and upbeat tone and style in her trainings (even virtually). Her gifts as a trainer are in creating an inviting space to learn, grow, and explore together. Her exceptional depth and breadth of experience and knowledge expands well beyond the course content and will enrich her students learning experience. 


Heather Imboden


Heather Imboden is a founding principal of Communities in Collaboration, a woman-owned evaluation and community engagement consultancy based in Oakland, California. Heather combines her skills in facilitation, outreach, and analysis with her expertise in community and economic development to lift community voice in partnership with diverse stakeholder groups for nonprofits, foundations, and government agencies. Heather’s work often focuses on advancing equity at the intersection of public education, workforce development, and neighborhood revitalization. She is also committed to local capacity development, striving to share her knowledge of the tools of engagement so that communities have a greater ability to advocate on behalf of themselves. In addition to her experience in community development, Heather’s background includes more than 15 years of experience in marketing and communications for nonprofits. Heather holds a Master of City Planning from the University of California, Berkeley, and a Bachelors of Arts from Wellesley College.

Penny Mabie 

Penny Mabie has been licensed by IAP2 to deliver the Certificate Program since 2009. She has more than 20 years of experience in public involvement, facilitation, and training. As a public involvement consultant, Penny provides facilitation and public participation services to support environmental remediation decision processes, infrastructure siting and design, multi-jurisdictional task forces on flood control, recycling and transportation planning, and national climate change initiatives. She has been an associate with EnviroIssues since 2000. She is also a roster member with the U.S. Institute for Environmental Conflict Resolution.

Penny Mabie

Cathy Smith


Cathy’s work in the inter-related fields associated with climate change—land use, transportation, water, energy, health—brings depth of knowledge and understanding of current engagement needs. As a past community mediator and practicing writer and storyteller, her engagement insights span from conflict management to communications. She’s one of 15 Certified Public Participation Practitioners in the country, a graduate of USD’s School of Law, and IAP2USA’s Past President.

Justin Schneider

Justin has more than 20 years of experience working with communities in the United States and abroad, focusing on p2/engagement, community development, community-based research, and legal work. Justin began his connection with IAP2 in 2018 and now supports the Lonestar Chapter. Currently, Justin is based in Austin, Texas and manages Oak Grove Community Consulting. He also works for Austin Parks and Recreation Department as a community engagement consultant and supports training within the organization. If you work for the City of Austin, please reach out to Justin before registering.


Craddock Stropes


Craddock Stropes (she/her) is a facilitator, trainer and coach with more than 25 years of experience in the local government and non-profit sectors. Her work centers on connecting people with ideas to create inclusive, strategic and tangible solutions that make everyday lives better. She is chair of the IAP2 USA Diversity, Equity and Inclusion committee, a member of the American Public Works Association national DEI Committee and is active in the International Network of Asian Public Administrators. She has presented learning sessions on inclusion, public engagement and crisis communications for Connect, California Association for Public Information Officers, Public Relations Society of America, American Public Works Association and Transforming Local Government conferences. She is currently a senior management analyst for the City of Carlsbad.

Doug Zenn

Doug Zenn has 30 years of experience in the communications field and has developed and managed community involvement, awareness, and education efforts around numerous issues including visioning, transportation, water resources, community-based planning and more. Doug has led ZennAssociates’ development of the innovative “Three-Dimensional Public Participation” model (3DP2) an approach that expands community access to project information and provides unique avenues for community input including the use of new technologies. Doug also serves on the executive committee for IAP2’s Cascade Chapter (Oregon and Southwest Washington) and is a certified trainer for IAP2’s public involvement foundations courses. Doug Zenn has 30 years of experience in the communications field and has developed and managed community involvement.



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