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Machine learning · Real estate

Estimating California home prices from listing data

Timeline
Sep 2026 – present
Team
IDX Exchange data science interns
My role
Data preparation, modeling, and evaluation
Skills
Python, CRMLS data, Regression, Feature engineering

Build a model that estimates the sale price of California homes from CRMLS listing data, and evaluate it on sales it has never seen.

  1. 01

    Tested on 12,500+ unseen sales

    All reported numbers come from a held-out set of more than 12,500 sales the model never trained on, so they reflect how it would behave on new listings.

    0.911R² on held-out sales

  2. 02

    Typically within about 8%

    Median absolute percentage error is 8.46%: on a typical home, the estimate lands within roughly 8% of the actual sale price.

    8.46%median APE

Next I want to understand where the model is least accurate, by region and price band, and make those errors visible rather than averaging them away.