Web: Used a dot to indicate new content in Discovery
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## Goal
Increase engagement and new channel discovery by increasing visits to the Discovery tab.
## What needs to be done
- Add a notification dot on the nav icon for Discovery that indicates new content.
- When the user navigates to Discovery, the dot is cleared
- The dot stays cleared for 24 hours
## QA
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Consideration is given to how the issue will be demoed and tested prior to being deployed
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## UX/Design
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Sufficient wireframes have been presented and understood by the development team. Full mockups are not required and re-usable components are encouraged.
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[Figma](https://www.figma.com/file/tHjd7fqgBiiTHRTNq5Ltfp/Web---Composer-and-Sidebar-updates?node-id=223%3A7879&t=89HUIWTvGeOE6Dx0-1) contains animation and hover states

**Spec sheet**

## Mobile
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Does a mobile card need to be created? Any notes for mobile?
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- [ ] Is Mobile Required?
## Personas
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Who does this user impact and why (optional)
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## Experiments
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Experiments are not required, but it should be made clear if one is expected. If experiments are required, the hypothesis should be outlined.
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- Implement as an A-B experiment
- Measure visits to Discovery page
## Acceptance Criteria
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Everyone should be able to understand what is expected to be delivered
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- [ ] Add a notification dot on the nav icon for Discovery that indicates new content.
- [ ] When the user navigates to Discovery, the dot is cleared
- [ ] The dot stays cleared for 24 hours
- [ ] Run as an experiment
## Definition of Ready Checklist
- [ ] Definition Of Done (DoD)
- [ ] Acceptance criteria
- [ ] Weighted
- [ ] QA
- [ ] UX/Design
- [ ] Personas
- [ ] Experiments
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