# Category 08 — Conversational Dialogue Systems

This category covers how AI systems *converse* rather than generate a single isolated reply. It spans turn-taking, grounding, repair, backchanneling, prosody, and multi-turn character consistency — from foundational Conversation Analysis theory (1970s–1990s) through 2024–2026 full-duplex speech LLMs. The humanization lens: dialogue is where "correct response" and "natural response" diverge most sharply.

## Angle files

- [A-academic.md](./A-academic.md) — 28 papers from CA theory (Sacks/Schegloff/Jefferson, Clark/Brennan, Yngve, Stivers) through neural dialogue benchmarks (Meena, LaMDA, BlenderBot, Sparrow) to full-duplex speech models (dGSLM, SyncLLM/EMNLP 2024, Moshi, VAP, LLaMA-Omni 2/ACL 2025, NVIDIA PersonaPlex) and evaluation metrics (SSA, USR, ACUTE-Eval, FLEXI/Sep 2025, LLMs-Get-Lost, HAL/Jan 2026). Updated April 2026.
- [B-industry.md](./B-industry.md) — 18 engineering and product blog posts from Google, Meta, OpenAI, Anthropic, Kyutai, Sesame, Hume (EVI 3/May 2025), Inflection, ElevenLabs (open-sourced Mar 2025), Deepgram, Rasa (CALM Spring 2026), Character.AI, and NVIDIA (PersonaPlex/Jan 2026); covers the convergence of a shared humanness taxonomy, the ~200 ms latency canon, the pipeline collapse toward end-to-end audio, and Anthropic's "character is not engagement" dissent. Updated April 2026.
- [C-opensource.md](./C-opensource.md) — 22 open-source repositories: Moshi (MoshiVis Jan 2026), Pipecat, LiveKit Agents, Ultravox v0.7, LLaMA-Omni 2 (0.5B–32B/ACL 2025), NVIDIA PersonaPlex (Jan 2026), Pipecat Smart-Turn v3.1, Stimm, RasaHQ/rasa (CALM v3.16/Spring 2026), ParlAI (archived), SpeechBrain, and adjacent voice stacks; documents the bifurcation between legacy intent frameworks and the 2024–2026 full-duplex wave plus the emergence of open-source semantic VAD. Updated April 2026.
- [D-commercial.md](./D-commercial.md) — 10 voice agent platforms (Bland, Retell, Vapi, Deepgram, ElevenLabs/open-sourced, Hume EVI 3, Sesame, LiveKit, Play.ai, Synthflow) and 5 text/omnichannel platforms (Intercom Fin, Ada, Cresta, Forethought, Kore.ai); maps the five commercial humanization dimensions and notes that Cresta is the only vendor to call out content-side spoken-style rewriting explicitly. Updated April 2026.
- [E-practical.md](./E-practical.md) — Practitioner voice from Reddit (r/LocalLLaMA, r/ChatGPT, r/AI_Agents), Hacker News, YouTube builder tutorials, and engineering blogs; documents the sub-800 ms perceptual cliff, backchannel-during-latency pattern, the #SaveStandardVoice revolt showing naturalness is non-monotonic with model quality, the five-generation endpointing taxonomy, and new 2025–2026 forum data on sycophancy measurement (SycEval) and persona drift benchmarks. Updated April 2026.

## Synthesis and legacy summary

- [SYNTHESIS.md](./SYNTHESIS.md) — the distilled synthesis across all five angles
- [INDEX.md](./INDEX.md) — legacy category summary — superseded by SYNTHESIS.md, preserved for traceability
