Standardization-Based Effect Estimation with Optional Prior Covariance Adjustment R package propertee version 1.0.6 The Prognostic Regression Offsets with Propagation of ERrors (for Treatment Effect Estimation) package facilitates direct adjustment for experiments and observational studies that is compatible with a range of study designs and covariance adjustment strategies. It uses explicit specification of clusters, blocks and treatment allocations to furnish probability of assignment-based weights targeting any of several average treatment effect parameters, and for standard error calculations reflecting these design parameters. For covariance adjustment of its Hajek and (one-way) fixed effects estimates, it enables offsetting the outcome against predictions from a dedicated covariance model, with standard error calculations propagating error as appropriate from the covariance model. Software Depends: R (>= 4.1.0) Imports: stats, methods, sandwich Suggests: knitr, rmarkdown, testthat (>= 3.0.0), multcomp, MASS Enhances: robustbase Josh Wasserman <jwass@umich.edu> Comprehensive R Archive Network (CRAN) Josh Errickson [aut], Josh Wasserman [cre, aut], Mark Fredrickson [ctb], Adam Sales [ctb], Xinhe Wang [ctb], Ben Hansen [aut] MIT + file LICENSE (https://CRAN.R-project.org/package=propertee/LICENSE) 2026-07-20 application/tgz https://CRAN.R-project.org/package=propertee doi:10.32614/CRAN.package.propertee