| What you get | What people say they think | What 12 curated people say behind a mirror | What people do when handed a device | What people actually do when they don't know they're being measured |
| The gap problem | Social desirability bias | Groupthink | Hawthorne effect | No gap. Observed behavior only. |
| Sample | 400–1,000 if they pick up (<6% response) | 8–12 curated, paid | 20–50 recruited, aware | Your entire room |
| Turnaround | Days to weeks | Days to schedule + interpret | Same day | Hours |
| Audience effort | Takes the survey | 2-hour commitment | Holds a device, told to react | Zero. They just attend. |