=== Supported Study and Messaging Designs ===
'''Shield currently supports these Study and Outreach Designs:'''
; * Preference-flip to control feature; * Preference-flip to control (disabled by default) system addon; * Add-on Based study (opt-in) [[Firefox/Shield/Shield_Studies|Shield Studies]]; * Add-on Based Study (opt-out) [[Firefox/Shield/Shield_Studies|Shield Studies]]: Recruits users to participate in testing new features and ideas that help us validate product decisions. Our users tell us what to ship. ; * [[Firefox/Shield/Heartbeat|Heartbeat]] Star Rating with action link; * Messaging Study with action link to external site (survey, Brain Games, interface testing, external user task tool); * Contextual Feature Recommendation: Customized action after user event; * Pioneer: On-going opt-in cohort for deeper data collection ; * Rollout preference study
=== Choosing A Design for Evaluating Features ===
