This task tracks the pre- and post-launch work for the Minimal Minerva Toolbelt (MinMin) experiment. It is adapted from the team's Experiment Launch Checklist.

Planned launch date: Aug 31

The experiment targets anonymous readers using Minerva on main-namespace pages. The configured GrowthBook tracking key is minimal-minerva-toolbar, with control and treatment variations.

Target Wikipedias: English, Persian, Czech, Bengali, and Polish.

Experiment link

https://growthbook.wikimedia.org/experiment/exp_g8hz53nms7mmyhg

Completed setup and implementation

• Core experiment implementation is complete: T428691: Implement experiment Minimal Minerva Toolbelt
• Control users receive the existing Minerva experience
• Treatment users receive the Minimal Minerva toolbar
• Experiment eligibility is limited to:
  • Anonymous users
  • Main-namespace pages
  • Minerva skin
• Experiment exposure events are implemented
• Experiment assignment is read from experiment platform data
• Local and development overrides are available
• Experiment is configured in GrowthBook
• GrowthBook variations include the intended experiment experiences
• Initial guardrail and secondary metrics have been created in GrowthBook
• Unnecessary overflow-menu and download instrumentation was removed
• ReaderExperiments hooks were refactored
• Lead-section truncation was separated behind a configuration flag and disabled for this experiment
• A post-experiment cleanup task has been created: T434652: [MinMin] Remove experiment

Completed bug fixes

• Edit icon follows the same logic as standard Minerva: T432995: MinMin toolbelt: edit icon should follow same logic as standard Minerva
• Fixed beta-cluster error caused by the former minimalMinerva flag: T433548: [beta cluster] MinMin toolbelt - Internal error for minimalMinerva flag
• Made the language selector keyboard-focusable: T433882: [a11y] Minimized toolbar - mw-interlanguage-selector is not keyboard-focusable

Before launch

Instrumentation and measurement

• Finalize the edit-based guardrail events: T434651: [MinMin] Finalize edit-based guardrail metrics
  • Confirm the final set of edit events required by the measurement specification
  • Produce edit_saved events containing mediawiki.database
  • Include page.revision_id so constructive edit rate can be calculated
  • Implement the agreed instrumentation
• Confirm all events in the instrumentation specification are marked complete
• Manually verify all specified events and payloads
• Verify instrumentation eligibility checks for anonymous users, main-namespace pages, and Minerva
• Verify experiment exposure events for both control and treatment
• Confirm GrowthBook’s experiment key, variations, metrics, and measurement specification agree

QA and bug bash

• Complete MinMin QA: T428690: QA simplified Minerva toolbelt on local/beta/test wiki
  • Beta
  • Patch demo
  • Post-deployment production check
  • Dark mode
  • Wide Minerva
  • Long article titles
  • Logged-in and logged-out states
  • Watch and edit states
  • Toolbar overflow behavior
  • Articles with varying comment counts
  • Language picker behavior
• Complete and close the focused bug bash: T428692: Minerva simplified toolbelt bug bash

Patched bugs awaiting final QA/signoff

• Confirm the Comments chip is hidden on wikis where talk pages at the top are disabled: T434559: [MinMin] Disable Comments chip in wikis where talk pages aren't allowed
• Confirm the Comments counter reflects the actual number of discussion topics: T433647: [beta & prod] simplified Minerva toolbelt - the Comments counter doesn't reflect the actual number of topics
• Confirm the Download button does not appear in MinMin on Android: T433619: [MinMin] Make sure the download button doesn't show up

Release readiness

• Confirm all required patches are deployed to production
• Confirm there are no launch-blocking regressions from the final QA pass
• Communicate the planned launch date to affected wikis
• Confirm whether any new MinMin message strings require translation review
  • English
  • Persian
  • Czech
  • Bengali
  • Polish

Immediately before launch

• Obtain final go/no-go signoff
• Complete final instrumentation QA: T434653: [MinMin] Launch experiment
• Schedule or start the experiment in GrowthBook before 14:30 UTC, Monday through Thursday: T434653: [MinMin] Launch experiment
• Record the experiment start time and expected end date in this task August 31, 2026 during deploy window

Post-launch

• Confirm both control and treatment users are being enrolled
• Validate experiment_exposure events in production
• Validate page_visit and toolbar click events in production
• Validate action_source and action_subtype values
• Validate edit guardrail events, including edit_saved, mediawiki.database, and page.revision_id
• Check event volume by target wiki for unexpected gaps or imbalances
• Confirm GrowthBook is receiving data for the primary, secondary, and guardrail metrics
• Document production-data QA findings in this task
• Monitor for regressions or community reports during the initial launch period

After the experiment

• Stop the experiment at the agreed end date
• Complete experiment analysis
• Remove MinMin experiment instrumentation and temporary experiment code: T434652: [MinMin] Remove experiment