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

This free online app allows datasets up to 15 mb.

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.