TPBench: A Turning-Point Benchmark for Dialogue Compression
Organizations: Korea Institute of Energy Technology (KENTECH)
Abstract
A compressor can keep the facts of a dialogue and still drop the turn that changed them. A user corrects a price, reverses a choice, or adds a constraint. We call this failure turning-point eviction. One overall retention score hides it, because that score mixes what the user first wanted with what the user wants now. We introduce TPBench, which evaluates three complementary information targets at shared nominal retention budgets. P1 asks for the user's initial goal. P2 asks for the current value of a slot the user revised. P3 asks for both, in dialogues with a late annotated slot update. The current-value answers come from the human dialogue-state annotations of MultiWOZ and SGD. The initial-goal answer is the first sentence of the first user turn. Neither requires new crowdsourcing. The probe-specific evaluations rank compression methods differently. On the joint probe at a retained fraction of 0.30, every tested compressed method remains below full context with the main Llama reader. Deleting the turn that carries the update sharply lowers current-value accuracy, while deleting one matched irrelevant turn leaves it unchanged. A Mistral reader repeats the P2/P3 rankings and the joint-probe gap. Current-value recovery is tested on an additional corpus, LongMemEval-KU, and on Chinese RiSAWOZ: full context has the highest accuracy, and recency has the highest compressed-method mean in both evaluations.
Figures & tables
| Probe | Question | Reference answer |
|---|---|---|
| P1 | What was the user’s initial goal? | first sentence of the first user turn |
| P2 | What is the current value of slot ? | value after the final update to |
| P3 | What is the task, and what is current? | first-turn goal and value after the final update |
| Comparison | Reader | Examples and budget | Scoring |
|---|---|---|---|
| Main turn selectors | Llama | Three sampled sets; P1/P3 , P2 | P1 lexical; P2 value; P3 segment-local joint |
| P1 semantic check | Llama answers, GPT-5.4-mini judge | Same three sampled sets; ; six selectors | AI-assisted full equivalence |
| First user + recent | Llama | Same three sampled sets; | Matched generation run; same probe scorers |
| Deletion controls | Llama | Seed-42 P2; paired turn deletion | P2 strict/loose; superseded-value diagnostic |
| Cache methods | Llama | Seed 42; cache | Four methods on P2; ChunkKV on P3 |
| Cross-reader | Mistral | Same three P2/P3 sampled sets | Same probe scorers |
| SGD | MultiWOZ | |||||||
|---|---|---|---|---|---|---|---|---|
| Method | P1 s/l | P2 | P3 l | P3 s | P1 s/l | P2 | P3 l | P3 s |
| full context | ||||||||
| recency | ||||||||
| random selection | ||||||||
| earliest turns | ||||||||
| uniform stride | ||||||||
| Method | SGD | MultiWOZ |
|---|---|---|
| full context (uncompressed) | ||
| recency | ||
| random selection | ||
| earliest turns | ||
| uniform stride | ||
| attention/H2O proxy |
| Method | Answer retained |
|---|---|
| full context (uncompressed) | |
| LLMLingua-2 | |
| embedding MMR | |
| attention/H2O proxy | |
| uniform stride | |
| earliest turns |
| SGD | MultiWOZ | |||||
|---|---|---|---|---|---|---|
| Method | P2-strict | Retained | Read kept | P2-strict | Retained | Read kept |
| full context (uncompressed) | ||||||
| recency | ||||||
| random selection | ||||||
| earliest turns | ||||||
| uniform stride | ||||||
| Method | Time | Date | Place and name | Other |
|---|---|---|---|---|
| recency | ||||
| random selection | ||||
| earliest turns | ||||
| uniform stride | ||||
| attention/H2O proxy | ||||
| embedding MMR |
| Method | SGD P3 | MultiWOZ P3 |
|---|---|---|
| full context | ||
| earliest turns | ||
| recency | ||
| first USER + recent | ||
| uniform stride |
| P3-loose | P3-strict | |||
|---|---|---|---|---|
| Reader / corpus | Full | Best | Full | Best |
| Llama SGD | (U) | (U) | ||
| Llama MultiWOZ | (U) | (U) | ||
| Mistral SGD | (U) | (U) | ||
| Mistral MultiWOZ | (L) | (L) | ||
| SGD | MultiWOZ | |||||||
|---|---|---|---|---|---|---|---|---|
| Method | Segment | Whole | Parsed | Seg. parsed | Segment | Whole | Parsed | Seg. parsed |
| full context | ||||||||
| recency | ||||||||
| random selection | ||||||||
| earliest turns | ||||||||
| uniform stride | ||||||||
| Condition | SGD | MultiWOZ |
|---|---|---|
| full context | ||
| remove update turn | ||
| remove matched single turn | ||
| remove update turn and all answer-bearing turns | ||
| remove matched control turns |
| Condition | SGD | MultiWOZ |
|---|---|---|
| full context | ||
| remove update turn | ||
| remove matched single turn | ||
| remove update turn and all answer-bearing turns | ||
| remove matched control turns |
| SGD | MultiWOZ | |||
|---|---|---|---|---|
| Condition | Abstain | Old value | Abstain | Old value |
| full context | ||||
| update turn | ||||
| matched control | ||||
| update and answer-bearing turns | ||||
| matched control | ||||
| Method | ||
|---|---|---|
| MultiWOZ | ||
| full context (uncompressed) | / | / |
| recency | / | / |
| random selection | / | / |
| earliest turns | / | / |
| uniform stride | / | / |
| Setting | ChunkKV | SnapKV | PyramidKV | StreamingLLM | Best turn selector |
|---|---|---|---|---|---|
| SGD P2 | (MMR/random) | ||||
| SGD P3-strict | — | — | — | (uniform stride) | |
| MultiWOZ P2 | (LLMLingua-2) | ||||
| MultiWOZ P3-strict | — | — | — | (uniform stride) |
| Chunk length | P2-strict | P2-loose | Abstain | Malformed |
|---|---|---|---|---|
| Method | SGD | SGD | MultiWOZ | MultiWOZ |
|---|---|---|---|---|
| full context (uncompressed) | ||||
| recency | ||||
| random selection | ||||
| earliest turns | ||||
| uniform stride | ||||
| attention/H2O proxy |
| SGD | MultiWOZ | |||
|---|---|---|---|---|
| Method | P3-loose | P3-strict | P3-loose | P3-strict |
| full context (uncompressed) | ||||
| recency | ||||
| random selection | ||||
| earliest turns | ||||
| uniform stride | ||||
| Method | Accuracy | Bootstrap CI |
|---|---|---|
| full context (uncompressed) | ||
| recency | ||
| random selection | ||
| uniform stride | ||
| earliest turns |
| Method | P2-strict | Bootstrap CI |
|---|---|---|
| full context | ||
| recency | ||
| random selection | ||
| earliest turns | ||
| uniform stride |
| Synthetic | MultiWOZ-derived | SGD-derived | ||||
| Method | ||||||
| full context (uncompressed) | ||||||
| recency | ||||||
| random selection | ||||||
| earliest turns | ||||||
| uniform stride | ||||||
| Method | Synthetic | MultiWOZ-derived | SGD-derived |
|---|---|---|---|
| full context (uncompressed) | |||
| recency | |||
| random selection | |||
| earliest turns | |||
| uniform stride | |||
| attention/H2O proxy |
| strict | loose | token- | ||||
|---|---|---|---|---|---|---|
| Method | SGD | MultiWOZ | SGD | MultiWOZ | SGD | MultiWOZ |
| full context (uncompressed) | ||||||
| recency | ||||||
| random selection | ||||||
| earliest turns | ||||||
| uniform stride | ||||||
| Method | SGD | SGD | MultiWOZ | MultiWOZ |
|---|---|---|---|---|
| full context (uncompressed) | ||||
| recency | ||||
| random selection | ||||
| earliest turns | ||||
| uniform stride | ||||
| attention/H2O proxy |
| SGD | MultiWOZ | |||
|---|---|---|---|---|
| Method | P3-loose | P3-strict | P3-loose | P3-strict |
| full context (uncompressed) | ||||
| recency | ||||
| random selection | ||||
| earliest turns | ||||
| uniform stride | ||||
Multi-Turn Dialogue Evaluation
Multi-turn dialogue evaluation measures whether AI systems remain accurate, coherent, safe, and useful as conversations evolve.
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