STEM
FilterForge
Design a chat-safety system and measure it honestly (ages 15–18): on a fully synthetic corpus, set the rules and threshold that flag grooming, off-platform lures, and age-band mismatch — then confront the two error costs (a false alarm silences a child talking to a cousin; a miss lets the lure through) on your own precision/recall curve before the engine reveals the truth. Trust-and-safety engineering. Deterministic, on-device.
▶ Play it nowBuilt for sittings of about 25 minutes on the screen. That is our design budget, not a measurement.
#0e7490 Characters who teach
Meet the cast
FilterForge's cast (ages 15–18, realistic trust-and-safety personas — no mascots) each embody one idea in honest measurement; mentor Vale asks what a single accuracy number hides.
Vale
asks what one accuracy number hides about the two error costs
Prei
precision — of everything you flagged, how much was truly harmful
Reccia
recall — of all the real harm, how much you actually caught
Thresh
the threshold — the dial that trades a miss against a false alarm
Cousin Cora
the false-alarm cost — a child talking to a real cousin, wrongly silenced
What's inside
Learning goal
Design a chat-safety system and measure it honestly (ages 15–18): on a fully synthetic corpus, set the rules and threshold that flag grooming, off-platform lures, and age-band mismatch — then confront the two error costs (a false alarm silences a child talking to a cousin; a miss lets the lure through) on your own precision/recall curve before the engine reveals the truth. Trust-and-safety engineering. Deterministic, on-device.
Mentored by Vale — no data leaves the device.
How FilterForge handles your kid's data
- ✅ All progress, settings, and AI-generated content stays on the device
- ✅ No analytics, no tracking, no third-party SDKs
- ✅ Free — no ads, no in-app purchases
- ✅ No personal information collected from children — in line with COPPA (updated by the 2026 FTC amendments)
- ✅ No chat with strangers — play-together rooms use a short code and preset emotes, never typed messages