  ShinyItemAnalysis (SIA) is an R package and shiny application for an
interactive presentation of psychometric methods and analysis of multi-item
measurements in psychology, education, and social sciences in general. In this
article, we present a new feature introduced in the recent version of the
package, called "SIA modules", which allows researchers and practitioners to
offer new analytical methods for broader use via add-on extensions. We describe
how to build the add-on modules with the support of the new SIAtools package
and demonstrate the concepts using sample modules from the newly introduced
SIAmodules package. SIA modules are designed to integrate with and build upon
the SIA interactive application, enabling them to leverage the existing
infrastructure for tasks such as data uploading and processing. They can access
a range of outputs from various analyses, including item response theory
models, exploratory factor analysis, or differential item functioning models.
Because SIA modules come in R packages (or extend the existing ones), they may
come bundled with their datasets, use object-oriented systems, or even compiled
code. We discuss the possibility of broader use of the concept of SIA modules
in other areas.
