# correctR

Corrected test statistics for comparing machine learning models on
correlated samples

## Installation

You can install `correctR`

from GitHub:

`devtools::install_github("hendersontrent/theft")`

## General purpose

Often in machine learning, we want to compare the performance of
different models. However, the methods used to obtain these performance
metrics (e.g., classification accuracy) violate the assumptions of
traditional statistical tests such as a \(t\)-test. Examples of these methods include
data resampling and \(k\)-fold
cross-validation. The purpose of these methods is to either aid
generalisability of findings (i.e., through quantification of error as
they produce multiple values for each model instead of just one) or to
optimise model hyperparameters. This makes them invaluable, but unusable
with comparative approaches such as a \(t\)-test, as Dietterich (1998)
found that the standard \(t\)-test
underestimates the variance, therefore driving a high Type I error.
`correctR`

is a lightweight package that implements a small
number of corrected test statistics for cases when samples are not
independent (and therefore are correlated), such as in the case of
resampling and \(k\)-fold
cross-validation. These corrections were all originally proposed by Nadeau
and Bengio (2003). Currently, only cases where two models are to be
compared are supported.