GIS/ValTech 2027

Start your morning with breakfast in the exhibit hall and take the opportunity to connect with exhibitors, explore new technologies, and discuss solutions that can support your GIS needs.

Most of us have interacted with Large Language Models (LLMs) like ChatGPT or Gemini through standard browser chat windows. However, this simple approach often leads to concerns about data privacy, security, and ongoing subscription costs. Furthermore, many of us have experienced model "hallucinations" or generic outputs that do not align with our specific appraisal processes, making AI results difficult to integrate safely into jurisdictional workflows.

This presentation addresses both of these critical issues. First, we will introduce a secure, open-source alternative: running powerful models locally on standard hardware using Hugging Face. This approach keeps your sensitive data entirely on-site and free from recurring API fees. Second, we will demystify how to use LangGraph to build structured, stateful workflows. Think of this as creating a custom map for your AI to follow. You will learn how to tightly control every step the model takes, dictate its actions after a decision is made, and choose exactly what tools (like local databases or calculators) it can access to aid its reasoning.

This session features an accessible introduction to these two open-source frameworks, followed by a step-by-step demonstration of a LangGraph agent facilitating daily efficiency in mass appraisal. Attendees will walk away with a practical understanding of local LLM's to help their offices start charting their own path and uncovering the hidden "rich stuff" in their data.


Keywords: Artificial Intelligence & Machine Learning, Mass Appraisal & Valuation Modeling, Advanced

This session follows a real-world continuous improvement project completed at the Maricopa County Assessor’s Office through the discovery and solution development phases for future improvements to the annual process of summarizing and reporting total values for approximately 2,500 taxing districts.

Attendees will learn how a variety of continuous improvement tools and techniques were used to identify underlying issues, uncover root causes, generate potential solutions, and prioritize improvement opportunities. While every Assessor's Office faces unique challenges, the principles and techniques presented can be adapted to identify opportunities, solve problems, and drive continuous improvement in any environment.

Matt Stellino, BS, PMP, Senior Data Scientist, Maricopa County Assessor’s Office - AZ

Keywords: Process Improvement & Operations, Beginner

The Netherlands is giving vertical equity analysis a modern makeover, moving from outdated tools to new metrics, international standards, and cutting-edge research. This session explores how Dutch assessors are incorporating IAAO standards, new equity measures, and practical online tools to better understand, monitor, and address vertical inequity.

Luc Hermans, Global Chief Officer/Data Scientist, Netherlands Council for Real Estate Assessment – Netherlands
Gijs Deen, Data Analyst, Netherlands Council for Real Estate Assessment - Netherlands

Keywords: Statistics & Ratio Studies, Assessment Equity, Intermediate

Maricopa County built a spatial tool in ArcGIS Experience Builder for comparing parcel characteristics and attribute data on an interactive map. Including properties, neighborhoods, subdivisions, parcel class, improvement areas, and more. With a huge parcel count, it enables parcel-level review and catches data inconsistencies through custom queries and filters. We'll cover how it works, how it was built, and its growing role and reputation as an office-wide data quality tool.

Orleans Parish applied that same "see it differently" idea to appeals. We'll walk an appeal end to end from submission, staff review, valuation, decision, documentation, and taxpayer communication. Then showing how digital workflows, AI-assisted valuation, and virtual assistance make the process faster, more transparent, and more consistent, without losing professional judgment.

30-minutes: Concept to Clarity: Inside Maricopa County’s Supplementary Valuation Tool
Keywords: GIS & Spatial Analysis, Mass Appraisal & Valuation Modeling, Intermediate
Sarah Sharp, GIS Specialist, Maricopa County Assessor's Office - AZ

60-minutes: The Future of Assessment Appeals Is Now: AI, Automation & Analytics
Keywords: Assessment Appeals, Artificial Intelligence & Machine Learning, Beginner
Brent Ardeneaux, RES, AAS, Residential Sales Modeler/Sales Validation Supervisor, Orleans Parish Assessor’s Office, LA
David Barnett, MAI, SRA, CEO, GAR Associates LLC - NY
Russell Almaraz, RES, AAS, Residential Modeler, Orleans Parish Assessor’s Office, LA

The best broad education in our field already exists. What is often missing is the hyper-local layer: your state's statutes, your CAMA system, your corner of the profession. In 2023, we set out to fill that local gap for our own community and built a peer-run conference from scratch.

This session tells the story of how a peer-run education conference grew from an idea between two people into a thriving annual event, and it hands you the practical blueprint to do the same. You will learn how to spot the gaps worth filling, recruit a founding team, choose a format and governance structure, fund the event without pricing anyone out, and draw both speakers and attendees from within your own community. Whether the need is software, appraisal, GIS, leadership, or something no one else is teaching, the grassroots model works.

Come and learn how to build affordable, peer-led education that your colleagues genuinely need, and that outlasts the people who start it.

Falon Hoven, Chief Deputy Assessor, Whatcom County - WA

Keywords: Workforce & Professional Development, Intermediate

Machine learning can do more than predict values. It can help us understand why properties behave similarly, identify meaningful comparables and adjustments, and reveal how markets organize themselves across space. This session moves from opening the machine learning black box to drawing data-driven neighborhood boundaries, showing how explainable AI, information theory, and even techniques borrowed from gerrymandering can turn complex algorithms into practical market insight.

Gerrymandering for Explainability: Automated Neighborhoods Using Gerrymandering Algorithms and Information Theory
Keywords: Artificial Intelligence & Machine Learning, GIS & Spatial Analysis, Intermediate
John Kossa, Data Scientist, Lee County Property Appraiser’s Office - TX

Explainable Machine Learning for Mass Appraisal: From Prediction to Market Insight
Keywords: Artificial Intelligence & Machine Learning, Mass Appraisal & Valuation Modeling, Advanced
Joe Wehrli, Enterprise Architecture Manager, Tyler Technologies - OH

The exhibition will close following this hour-long break. Use these final 60 minutes to gather the specifications and information you need to make informed solutions decisions for your organization—and don’t miss your name being called during the raffle prize drawings!

This presentation examines the core assessment issues of uniformity, valuation, and taxpayer impact through an interactive mapping case study spanning ten years and 1.8 million parcels in Cook County, the second-largest assessment jurisdiction in the United States. The scale of the data presents significant analytical challenges, including outliers, classification complexities, and changing valuation patterns.

The study revisits the foundational work of Homer Hoyt, whose 1933 landmark analysis, starting in 1830, linked Chicago land values to race, rents, income, and urban growth. It also builds upon the research of Gabriel Ahlfeldt and Daniel McMillen, who documented how transportation, economic change, and neighborhood density influenced land values between 1913–2010.

By comparing Cook County land valuations from 2016–2025 with studies spanning 1830–2010, the presentation identifies major divergences in land-value patterns across centuries. It explores the practical implications of assessment policies and taxation shifts in Cook County, Illinois, the second-highest property tax jurisdiction in the nation with the highest tax delinquencies and increasing land-based appeals. Cook County’s 30 miles of Lake Michigan shoreline includes some of the most valuable urban and suburban land in the Midwest. Land value now represents an increasingly significant component of property assessment, creating new challenges for assessors, taxpayers, and assessment professionals.

The study leverages customized proprietary software, QGIS, and other GIS tools to analyze assessment characteristics, land values, and spatial patterns. We demonstrate why assessors, assessment and legal professionals should develop their own land valuation analysis, visualization tools, using open-source and in-house technologies.

Andrea Raila, Senior Tax Analyst, Raila & Associates - IL

Keywords: GIS & Spatial Analysis, Assessment Equity, Mass Appraisal & Valuation Modeling, Beginner

Hard Conversations Happen! Are you prepared to navigate difficult situations gracefully and generate positive outcomes? From exchanging simple feedback to facilitating passionate debate, this session explores the profound impact we have on one another and how to cultivate a culture of clear, open, and professional communication. Learn to address challenging workplace topics head-on while navigating the personal realities that can impact productivity. Want to discover the core of what makes professional relationships thrive? Come see how culture and communication can overcome enormous obstacles, even elephants in the room!

Phillip Leveille, GIS Specialist Supervisor, Maricopa County Assessor’s Office - AZ

Keywords: Leadership & Communication, Beginner

Machine learning may produce great valuations, but can you explain and defend them when someone challenges the result? This session puts ML on the witness stand, exploring how models perform against IAAO ratio study standards, how complex predictions can be translated into explanations taxpayers and appeals boards can understand, and how assessors can build the documentation needed to make machine learning valuations defensible

Will Jarvis, CEO and Founder, Valuebase - NC

Keywords: Artificial Intelligence & Machine Learning, Assessment Appeals, Statistics & Ratio Studies, Beginner