Thirteen agents.
Zero evaluation.
One decision model.
The Decision Capture Platform records how learners make spelling decisions using Merriam-Webster pronunciation as the fixed reference. Built on Dr. Robert T. Nash's Pure and Complete Phonics — 103 phonemes, 47,000 words, 70 years of research. Every agent observes. None evaluates. The teacher decides everything.
Student Interface
4-stage workflow. Typed input only — no voice. MW pronunciation symbols as fixed anchor. Dialect-neutral by design.
Server · Node.js + Express
3,619-line server.js. Redis rate limiting, magic-link auth, Anthropic Claude Haiku for Socratic Coach AI. 30s timeout on coach proxy. RLS on every Supabase table.
Agent Layer · 13 Agents
Scheduled cron + fire-and-forget. Pattern observation, student profiling, IEP goal drafting, difficulty tracking, live alerts. All enforce the Decision Capture Model constraint.
Supabase · Postgres
Users, records, student_profiles, iep_drafts, live_alerts, session_debriefs, vocabulary_bank. Service role key. Row Level Security on every table.
Four stages. Every decision recorded.
Thirteen agents. Three layers.
The Decision
Capture Model
Every agent, every API response, every robot behavior operates under one inviolable constraint: observe and record. Never evaluate. The platform captures spelling decisions exactly as made. The teacher interprets everything.
No agent or interface may use: correct, wrong, right, close, almost, good job, great, nice, perfect, exactly, or well done. No evaluation in any form.
The same brain.
A physical presence.
No new API endpoints. No new agents. The robot is a client — like the browser, but with a body. It points, nods, tilts its head, pulses its chest LEDs for high-variation phonemes, and delivers Coach responses with a voice. The intelligence stays server-side. The robot adds the relationship.
The brain, embodied.
This is NOT the web app in a robot shell. The robot IS the interface. It presents sounds, holds up phoneme cards, displays the word on its chest screen, and coaches through gesture and voice. The student's tablet is mounted on the robot — every interaction goes through the companion.
Stage-by-stage behavior map.
Every robot gesture, posture, speech act, and LED cue mapped to the four-stage Decision Capture workflow. The robot is a client of the existing API — the intelligence stays server-side.
| Trigger | Robot Behavior | Platform Connection |
|---|---|---|
| Student opens app | Sits up straight, eyes brighten (LED), turns head toward student. Says: "Ready when you are." | Robot client loads /api/session-context for student profile. |
| Student types word | Leans slightly forward (interest posture). Watches screen. Silent. | No API call — local screen monitoring only. |
| Student enters MW pronunciation | Nods once slowly. Eyes track from screen to student briefly. | Robot parses pronunciation locally to pre-load sound sheet data. |
| Student clicks Create Syllables | Gentle "let's go" gesture (one arm forward). Says: "Syllables are set. Time to map the sounds." | Stage transition logged locally. Timer starts for engagement tracking. |
| Student idle > 30 seconds | Tilts head quizzically. Says: "What step are you on?" | Sends idle signal to /api/guide with context for Socratic prompt. |
| Trigger | Robot Behavior | Platform Connection |
|---|---|---|
| Student selects phoneme | Points toward screen's phoneme area. Plays matching .mp3 from /audio/ through speaker. | Maps selected phoneme to local audio file (e.g. \ə\ → schwa.mp3). |
| Student types grapheme | Watches. No reaction. (DCM: observe, never evaluate) | None — platform records, never grades. |
| Student selects position 3+ | Raises eyebrows slightly (curiosity, not judgment). Stays silent. | None. Higher position is recorded, not evaluated. |
| Student marks letter silent | Slow single blink (acknowledgment). No verbal response. | None. |
| Student pauses > 45 seconds | Says: "Say the sound slowly. What do you hear?" Leans in slightly. | Fires /api/guide with stuck-student context. Coach returns Socratic question. |
| Frustration detected (camera) | Leans back (gives space). Eyes soften. Says: "Take your time. There is no rush." | On-device ML only. Categorical label. Never streamed or stored. |
| High-variation phoneme (e.g. schwa) | Chest LED pulses teal — subtle cue that this sound has many spellings. No verbal comment. | Checks sound-sheets.js: if totalGraphemes ≥ 5, triggers LED pulse. |
| Trigger | Robot Behavior | Platform Connection |
|---|---|---|
| Student clicks Build Word Output | Sits up, both hands come together (anticipation gesture). | None. |
| Built word matches original | Slow affirming nod. Eyes brighten. Says: "The letters line up. Ready for the last part?" | Structural match — not evaluative. Robot never says "correct." |
| Built word does NOT match | Tilts head. Says: "The built word looks different. Which row might need a second look?" | Sends mismatch context to /api/guide for targeted Socratic question. |
| Trigger | Robot Behavior | Platform Connection |
|---|---|---|
| Student writes spelling reflection | Leans in slightly — this is the most valuable data point. | None. |
| Student submits record | Celebratory micro-gesture: arms rise briefly, eyes flash (3 seconds max). Says: "That one is recorded. Want to do another word?" | POST /api/records. Server triggers session-debrief and live-alerts agents. |
| Student ends session | Relaxes posture, eyes dim gently. Says: "Good session. See you next time." | Session end logged. Robot client disconnects. |
Five states. Camera optional.
| State | Physical Expression | Verbal Tone | Transition Trigger |
|---|---|---|---|
| READY | Upright, eyes forward, calm breathing animation | Warm, even pacing | Session start or return from break |
| ENGAGED | Slight forward lean, eyes tracking screen | Slightly more animated | Student actively typing/selecting |
| CURIOUS | Head tilt, eyebrow raise, gaze shifts | Inquisitive inflection | High-variation phoneme or unusual selection |
| PATIENT | Lean back, slow breathing, eyes soft | Slower, gentler pacing | Frustration detected or idle > 60s |
| CELEBRATING | Brief arm raise, eye flash, slight bounce | Upbeat but brief (3 seconds max) | Record submitted successfully |
The CELEBRATING state lasts a maximum of 3 seconds. The robot celebrates completion of effort, not correctness. This aligns with the platform's absolute ban on evaluative language.
| Component | Spec | Purpose |
|---|---|---|
| Touchscreen | 10" capacitive (1920×1200) | Runs DCP student interface |
| Compute | Raspberry Pi 5 (8GB) | RBL client, local ML, behavior state machine |
| Camera | 720p, on-device only | Engagement detection (never streamed/stored) |
| Speakers | 2W stereo | TTS coach responses + phoneme audio |
| Head Servos | 2-axis pan/tilt | Nod, tilt, turn toward student |
| Eye Display | 2× OLED 1.3" | Emotional expression |
| Chest LEDs | RGB addressable strip | Status + high-variation phoneme pulse |
| Battery | 10000mAh + UPS HAT | 4+ hours active use |
| Enclosure | 12-18" tall, soft-touch | Child-safe, desk-sized companion |
Robot Behavior Layer
The same thirteen agents. The same Decision Capture Model. Embodied in a physical coaching companion. The robot adds presence, not intelligence — the brain already exists.