Sentiment Classifier Scenarios - MangaAssist
This companion document grounds sentiment fine-tuning in MangaAssist. The goal is not generic positive/negative sentiment; the goal is to detect frustration, urgency, and escalation risk inside shopping and support conversations.
When This Topic Matters
Use a fine-tuned sentiment or frustration classifier when:
- users ask for a human agent,
- repeated support loops create frustration,
- a neutral support message hides urgency,
- routing should become more conservative.
Scenario 1 - Frustration Detection For Escalation
Example messages:
"I already asked this twice. Where is my order?"
"This refund answer is useless."
"Can I please talk to a real person?"
Labels:
| Label | Meaning |
|---|---|
| calm | normal shopping or support |
| confused | user needs clarification |
| frustrated | negative experience but recoverable |
| escalation_needed | human handoff likely |
Training setup:
| Setting | Value |
|---|---|
| Base model | DistilBERT or same shared encoder as intent |
| Dataset | 20K support and shopping turns |
| Loss | class-weighted cross entropy or focal loss |
| Special metric | recall on escalation_needed |
Promotion gate:
| Metric | Gate |
|---|---|
| macro F1 | >= 88% |
| escalation-needed recall | >= 92% |
| false escalation rate | <= 8% |
| P95 latency | <= 10 ms |
Scenario 2 - Conversation-Level Sentiment
A single message may look calm, but the conversation pattern can show frustration.
Features:
- repeated question count,
- low-confidence answer count,
- user reformulation count,
- negative words,
- time since first issue.
Use a small sequence model or aggregate features around the message classifier.
Scenario 3 - Sentiment-Aware Routing
Routing policy:
if intent == escalation or sentiment == escalation_needed:
offer human handoff
elif sentiment == frustrated and confidence_low:
ask direct clarifying question
else:
continue normal flow
Failure Modes
| Failure | Detection | Fix |
|---|---|---|
| sarcasm missed | negative CSAT despite calm label | add reviewed sarcasm examples |
| anime slang misread | "this manga is sick" labeled negative | domain-specific labels |
| false handoffs too high | support queue grows | calibrate threshold |
| frustration ignored in multi-turn | repeated complaints | add conversation features |
Production Log
{
"event": "sentiment_route",
"intent": "order_tracking",
"sentiment": "frustrated",
"frustration_score": 0.86,
"turn_count": 5,
"decision": "offer_human_handoff"
}
Final Decision
For MangaAssist, sentiment fine-tuning should optimize for operational safety. Missing frustrated users is more harmful than occasionally offering a human handoff too early.