Cornell University · Protocol IRB0151136

Online Grocery Study — Privacy Notice

Browser extension Last updated 10 September 2026

The Online Grocery Study extension records what you look at and what you buy on Walmart.com, and nothing else. It never sees your Walmart login, your payment details, or any other website.

Your data is stored under a random study code, not your name, and is used only for this research.

1Who we are

This extension is part of a research study run by researchers at Cornell University and Stanford University, approved by the Cornell University Institutional Review Board under protocol IRB0151136. It is distributed only to people who have consented to take part. It is not a commercial product, and it is not affiliated with, endorsed by, or operated by Walmart Inc.

2What the extension records

Only on walmart.com, and only while you are signed in and taking part in the study:

A study code A random identifier such as p-4820175093-1. It is not derived from your name, your email, or your Walmart account.
Which kind of Walmart page you are on Search and browse pages, product pages, and your cart.
The products shown to you Product name, item number, price and position on the page. We record the full set of options you saw, not only the ones you chose.
The contents of your cart Product name, item number, price and quantity.
Your past Walmart orders Read once, from your Walmart order history, so we can see what you normally buy.
How you interact with the study's own on-screen elements Whether a nutrition score was shown, hovered over or dismissed, and whether the gift card was shown and opened.
A copy of the visible content of those pages Personal regions are removed inside your browser before anything is sent. See section 3.
Your answers to the study's own questions Age band, sex, height, weight, activity level, health conditions, dietary preferences, and household composition. Every one of these may be skipped.
Technical details Whether you are signed in to Walmart (yes or no), the extension version, and timestamps.

3What the extension never records

Your Walmart username or password You sign in on Walmart's own page. The extension never sees, stores or transmits any credential, and never asks you for one.
Your payment details No copy of the checkout page is ever recorded and no payment information is read. The only thing recorded at checkout is that the study's gift card was displayed.
Your order confirmation page Excluded entirely, because it carries your order number and delivery address.
Your name, email address, postal address or phone number Page headers, navigation, account areas, delivery and store details are stripped out inside your browser, and the remaining text is scanned for email addresses, phone numbers, card digits and postal codes, which are removed, before anything leaves your computer.
Anything on any other website The extension runs only on walmart.com. It cannot read any other site, and it does not track you across the web.
Anything on the gift card page On the page where your gift card opens, the extension only highlights which button to press. It reads nothing and sends nothing from that page.

4Where the data goes

Records are sent to a private research database hosted on Supabase and are accessible only to the study's researchers. The database is configured so that the extension can add records but cannot read back anyone's data, including your own.

Data are not sold, rented, or shared with Walmart, with advertisers, or with any other third party. They may be shared in de-identified form with collaborating researchers, or as required by law.

5How the data is used

Data collected by this extension are used solely to conduct and analyse this research study, and for no other purpose. In particular, they are not used for advertising, for building marketing profiles, for credit or lending decisions, or for training generative artificial intelligence models. Data are not transferred to anyone except as described in section 4, and no human reads individual records except the study's researchers, and only for research purposes.

6How long we keep it

Study records are retained for the period set out in the approved research protocol (IRB0151136) and are then destroyed. Because records are stored under a random study code rather than your name, they cannot be linked back to you by anyone outside the research team.

7Taking part, and stopping

Taking part is voluntary. You may stop at any time by removing the extension from your browser, and you do not need to tell us or give a reason. Removing the extension stops all further collection immediately.

To ask that records already collected be deleted, email the study contact below with your study code. You can find your study code by clicking the extension's icon in your browser toolbar.

8Changes to this notice

If what the extension collects changes, this page is updated and the date at the top changes with it. Changes that materially affect participants are also communicated directly, and where required, reviewed by the Institutional Review Board before taking effect.

9Contact

Cristiana Firullo · Cornell University
cf528@cornell.edu

For questions about your rights as a research participant, or to report a concern about the study, contact the Cornell University Institutional Review Board, referencing protocol IRB0151136.