
A common interface for several methods to calculate the
Expected Value of (Partial) Perfect Information and the
Expected Value of Sample Information
A project of the ConVOI Group: the Collaborative Network for Value of Information
Comparison with other packages
voi
is pure “commandbased” R, with no web interface like SAVI.
The R commands in
voi
are clean and consistent: they all have the same basic interface, so you can switch between computational methods easily.Outputs are all in “tidy” data frames for consistency, and to facilitate postprocessing and plotting with modern tools such as ggplot2.
EVPPI computation
voi
includes all the EVPPI computation methods that are in SAVI (GAM and Gaussian process regression), and includes the INLA method from BCEA.Some other nonparametric regression methods (
"earth"
,"bart"
) are included invoi
, which may improve efficiency for multiparameter EVPPI computation problems with large numbers of parameters.
EVSI computation

voi
is the first package to implement a range of EVSI computation methods: nonparametric regression, moment matching and importance sampling. A simple model for the expected net benefit of sampling is also included.
Installation
Stable version
install.packages("voi")
Development version
remotes::install_github("chjackson/voi")