AssessR is a software package for R developed by the Cook County Assessor’s (CCAO) Data Department. This package is used in the CCAO’s custom-built Automated Valuation Model (AVM). The codebase for the CCAO’s AVM uses a wide range of functions regularly, and packaging these functions streamlines and standardizes their use.

For assessors, we believe that this package will reduce the complexity of calculating ratio statistics and detecting sales chasing. We also hope that reporters, taxpayers, and members of academia will find this package helpful in monitoring the performance of local assessors and conducting research.

For detailed documentation on included functions and data, visit the full reference list.

For examples of specific tasks you can complete with assessr functions, see the vignettes page.

You can install the released version of assessr directly from GitHub with one of the following commands:

# Using remotes
remotes::install_github("ccao-data/assessr")

# Using renv
renv::install("ccao-data/assessr")

# Using pak
pak::pak("ccao-data/assessr")

# Append the @ symbol for a specific version
remotes::install_github("ccao-data/[email protected]")

Once it is installed, you can use it just like any other package. Simply call library(assessr) at the beginning of your script.