DealSpotter is a Craigslist search tool created by Chris Said that uses random forests and regular expressions to detect good car deals. It scrapes Craigslist data to predict fair prices based on a car's model, year, and mileage, then highlights listings that are significantly below the predicted price. The tool is built using technologies like d3.js, Beautiful Soup, and regular expressions, and the creator has a PhD in neuroscience from Princeton and was a postdoc at NYU.

1. DealSpotter
Chris Said

2. Craigslist Search

3. Craigslist Search

4. Web Scraping
Needs regular expressions!

5. Pricing Model

6. Random Forest Pricing Model
Random
Forests
detect
discontinuities
in
prices
Price = f(model, year, mileage)
$22K
2000
$6K
$10K
$14K
$18K
2005 2010 2015
Year
Modelpriceprediction
Honda Accord
design overhauls

7. Stack
d3.js
Beautiful Soup
Regular
Expressions

8. About Me
NEW YORK UNIVERSITY
• My name is Chris Said
• PhD in Neuroscience and Psychology - Princeton University
• Postdoc at the Computational Neuroimaging Lab - NYU
• I like hiking and camping

9. Summary
DealSpotter makes it easy to find the best car deals on
Craigslist. DealSpotter knows how much each car should
be priced, based on its year and mileage. Cars that are
priced much less than expected are shown at the top of
the list. In graph mode, good deals are highlighted in blue.