Johnson-Neyman 2.0: Online App for Nonlinear Probing of Interactions

This online app allows you to run GAM probing of interactions, computing GAM Simple Slopes and GAM Johnson-Neyman. It uses the function interprobe in the R package statuser for calculations.

To proceed:

Upload the data
Select a focal predictor, moderator, and dependent variable from the list of variables in it
Click the Run button
Get publication-ready figures

For a tutorial see
Montealegre & Simonsohn (2026) “Johnson-Neyman 2.0”, under review, Journal of Consumer Research

For background see
Simonsohn, U. (2024). Interacting with curves: How to validly test and probe interactions in the real (nonlinear) world. Advances in Methods and Practices in Psychological Science, 7(1), 1–22. https://doi.org/10.1177/25152459231207787

Upload your data

No file handy? Download this example datafile and upload it.

Data privacy information

Uploaded data is deleted within 72 hours. Files are saved unencrypted in a public folder but given a temporary name, so they are hard to find but not impossible to locate. For confidential data, run the analysis locally in R instead of uploading here.