Exploring the Data

When you downloaded the JSON file from REX Demo, you got a snapshot of everything the extension collected. This guide explains how to read it and what to look for.

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What the file contains

The file is a JSON array: a list of records, one per data event. Each module decides the fields in its own records, but every record has two things in common:

• name: the kind of record, such as rex-history-visit for a page visit or rex-conversation for a ChatGPT conversation
• passive-data-metadata: where the record came from: the participant or study ID (source), the record type (generator-id), when it happened (timestamp, in seconds since 1970), and the browser’s time zone

Here is a shortened record from rex-history:

{
  "name": "rex-history-visit",
  "url": "https://example.com/",
  "domain": "example.com",
  "title": "Example Domain",
  "visit_time": 1736952721000,
  "transition_type": "link",
  "passive-data-metadata": {
    "source": "test-001",
    "generator-id": "rex-history-visit",
    "timestamp": 1736952721,
    "timezone": "America/Chicago"
  }
}

The transition_type field tells you how the participant reached the page: "link" means they clicked a link, "typed" means they typed the address, and so on.

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How to explore the file

The easiest way to browse a JSON file without any software is a free online viewer. Try jsonviewer.stack.hu: paste your file contents in and it shows a collapsible tree.

If you use VS Code, you can open the file directly. Right-click anywhere in the file and choose “Format Document” to make it readable. VS Code also lets you collapse and expand nested objects.

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What to look for

The generator field is your guide to understanding what you are looking at. Each value corresponds to a REX module:

• rex-history-visit: one record per page visit, from the browser’s history
• rex-conversation: one record per chatbot conversation, from the spider modules (not in the demo)

If rex-demo includes other modules, you will see additional generator values. The Module Overview maps each generator to its module and explains what its payload fields mean.

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Deciding if REX fits your study

The simplest test: do you see the data your study needs in this JSON?

If yes, REX collects it. The next step is understanding which module produces it and whether that module is straightforward to include in your extension.

If you do not see what you need, check the Module Overview. A different module might capture it. Some data types, such as chatbot conversations and search results pages, need modules the demo doesn’t include.

If you are still not sure whether REX can collect what you need, email BRIC.

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Next step

Module Overview: a plain-language description of every REX module, what each one collects, and which ones are relevant for common research questions.