In-person and Online: Generating 1.9 Million HTML Pages to Explain How the Cook County Assessor’s Statistical Model Assessed Your Home​ #656

The Data team at the Cook County Assessor’s Office (CCAO) is responsible for estimating the value of over a million homes in Cook County using public sales data. We do that using a boosted tree model that is less regressive and more accurate than linear models, and while our model is relatively simple as far as models go, it can be difficult to explain how it works in a clear, accessible way. We can talk about things like tree depth, SHAP values, and vertical equity statistics all day, but what most people want to know is: “What sales did the model use to value my home?”

Enter the CCAO Model Value Report: A web app that shows all of the property characteristics the CCAO’s model used to value your home, alongside the top five sales that were most important to the model’s estimation of your value.

In this talk, the CCAO Data team will explain how and why we built the Model Value Report. We’ll talk about the questions we want the app to answer for homeowners, the UX design decisions we made to help answer those questions, and the nitty-gritty details of how we built it all – from the development of a brand new AI explainability algorithm, to the scaling of that algorithm across all homes in the County using high-performance Python code, to the 1.9 million static HTML pages that our Hugo app can generate and deploy in under an hour.

This event will be in person, but you can also tune in via livestream. Doors open at 6pm. The livestream and announcements will start around 6:30pm CDT.

In-person: i.c.stars, 750 N Orleans, Suite 500 (5th floor), Chicago IL.

For more information on our in-person events, please see our COVID Policy.

RSVP In-person attendees should RSVP beforehand. As occupancy limits permit, walk-ins will be allowed to enter.

There will be food! We will be serving Costa Rican empanadas, chicken casado and rice from Irazu!