> ## Documentation Index
> Fetch the complete documentation index at: https://docs.winningvariant.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Overview

> All about Winning Variant experimentation assignments.

Winning Variant defines an "assignment" as the variant a [subject](resources/subjects) is assigned within an experiment.

## Example

Imagine you have a series of experiments running on your website:

| Experiment ID     | Description                                                        | Subject Type   |
| ----------------- | ------------------------------------------------------------------ | -------------- |
| `HOME-CTA`        | Red/blue/green CTA button on home page                             | `ANONYMOUS_ID` |
| `CART-NOTICE`     | Show a notice after 30s to improve cart abandonment.               | `ANONYMOUS_ID` |
| `FEATURE-CALLOUT` | Show a new feature callout in-app and see if engagement increases. | `USER_ID`      |

Vanessa is a known user on your platform. When she accesses your website, she has two subject IDs:

1. Anonymous ID (`ANONYMOUS_ID`): `anon_0001`
2. Known User ID (`USER_ID`): `user_0001`

If Vanessa enters all 3 experiments, she'll have 3 assignments:

| Experiment ID     | Subject ID  | Assignment ID    | Experiment Variant |
| ----------------- | ----------- | ---------------- | ------------------ |
| `HOME-CTA`        | `anon_0001` | `assignment_001` | `RED`              |
| `CART-NOTICE`     | `anon_0001` | `assignment_002` | `TREATMENT`        |
| `FEATURE-CALLOUT` | `user_0001` | `assignment_003` | `FEATURE-A`        |

## Context

Assignments are immutable (with a few administrative exceptions) and contain context to when they are created. Specifically, an assignment has timestamp of when it was created and the cohort number within the experiment they entered in. This allows you to properly attribute a subject's actions to their cohort and/or when they first experienced an experiment.

## Assignment Data

[Read more about the raw assignment data](/analytics/assignments) that's provided from the application.