Conjoint Companion Shiny App

This repository contains the R Shiny source code behind the companion web app for the paper. It is meant as an educational source overview for readers who want to see how the publication workflow is implemented and what happens in the background.

• Live web app: https://shiny.drdiscipulus.de/conjoint_app/
• Paper: https://doi.org/10.1177/10422587231184071
• Desktop app: https://github.com/drdiscipulus/conjoint_desktop_app

The repository is not intended as an active-development project or as a release channel. It intentionally keeps only the files needed to run the Shiny app, the public demo data, and documentation.

What The App Does

The app supports two conjoint-related workflows:

1. Generate full and fractional factorial designs for conjoint experiments.
2. Run the test-retest reliability workflow described in the accompanying paper: Test-Retest Reliability in Metric Conjoint Experiments: A New Workflow to Evaluate Confidence in Model Results.

How The App Is Built

• app.R is the entry point. It loads packages, sources helper files, defines the Shiny navbar, and starts the app.
• ui/ contains the tab layouts and explanatory screens shown in the browser.
• server/ contains the tab-specific server logic for factorial design generation and test-retest reliability analysis.
• R/ contains focused helpers for upload validation, temporary session files, result exports, labels, UI components, alias diagnostics, and interaction coverage checks.
• functions_factorial.R, functions_reliability.R, and custom_corr_plot.R contain the older workflow-specific statistical and plotting helpers that the app still sources directly.
• scripts/run_app.R is a small launcher for running the app from the command line.
• demo_data.csv and demo_data.xlsx are public sample files for trying the reliability workflow.

Local Setup

Install the required R packages before running the app:

install.packages(c(
  "shiny", "shinyjs", "shinycssloaders", "bslib",
  "tidyverse", "reactable", "FrF2", "DoE.base", "broom", "psych",
  "sandwich", "lmtest", "parameters", "plotly", "viridis", "vroom",
  "openxlsx", "prismatic"
))

This repository documents dependencies but does not pin them with renv.

Run Locally

Rscript scripts/run_app.R

From R, the same app can be started with:

shiny::runApp(".")

Input Format

Reliability uploads must be .csv or .xlsx files with exactly one table. The required columns are:

• respondent
• round
• profile
• dv
• at least two attribute columns named with the prefix att_

The round, profile, dv, and att_ columns must be numeric or cleanly coercible to numeric. The round column must contain exactly rounds 1 and 2.

Current upload limits:

• maximum file size: 5 MB
• maximum rows: 25,000
• maximum columns: 250

Outputs

After a successful reliability analysis, the app can export:

• an XLSX workbook with reliability, slope-difference, and pooled-regression tables in three sheets: Reliability table, Slope Difference, and Pooled Regression,
• a ZIP archive with the same three result tables as separate CSV files.

Plots can be downloaded from the Plotly toolbar in the app.

Privacy And Data Handling

Uploaded data and generated result files are processed in a session-specific temporary directory. The app registers cleanup at session end and removes session-generated files on reset. User-provided filenames are used only for display/format checks, not for internal paths.

Maintenance

This repository is maintained occasionally and conservatively. The statistical workflow should remain stable unless a specific bug is identified.

Citation

If you use the app, source code, or workflow in research or teaching, please cite the article:

Schueler, J., Anderson, B. S., Murnieks, C. Y., Baum, M., & Kuesshauer, A. (2024). Test-Retest Reliability in Metric Conjoint Experiments: A New Workflow to Evaluate Confidence in Model Results. Entrepreneurship Theory and Practice, 48(2), 742-757. https://doi.org/10.1177/10422587231184071

Machine-readable citation metadata are available in CITATION.cff.

License

This project is licensed under the GNU General Public License v3.0. See LICENSE.

R Shiny app written by Jens Schueler.