transcript chunking agent split mid-sentence, qa answers wrong

TL;DR

Splitting transcripts mid-sentence breaks Q&A because the question's context lands in a different chunk than its answer. Chunk on speaker turns and Q&A boundaries with sentence-aware overlap, so each chunk holds complete exchanges.

The error

qa: 'What was Q3 guidance?' was answered from chunk 12 (analyst question) while the CEO answer was in chunk 13.
Answer: wrong (cited the question as the answer).

Fix it

1. Re-chunk the transcript on speaker-turn boundaries: never split inside a speaker's continuous turn, and keep each Q&A pair (question plus answer) in one chunk. Expected: Expected: the question and its answer coexist in the same chunk.

2. Add sentence-boundary enforcement with overlap: chunks share the last 2-3 sentences so boundary context survives. Expected: Expected: no chunk starts or ends mid-sentence.

3. Re-run the failed Q&A queries against the re-chunked transcript and verify the answers cite the correct speaker. Expected: Expected: the guidance question now answers from the CEO's turn with the right figure.

4. In the pipeline, validate chunks mechanically: every chunk must start at a speaker label and end at a sentence boundary. Expected: Expected: malformed chunks fail at build time, not at query time.

When to use

• Your transcript Q&A gives wrong answers because context split across chunks.
• You need chunking that respects conversational structure.
• You run RAG over earnings call transcripts.

When not to use

• The transcript is a monologue - then sentence chunking suffices.
• The wrong answer comes from retrieval ranking, not chunking - check the retriever.
• You chunk by fixed tokens for cost reasons - then at least add the overlap.

Why it happens

Token-based chunking cuts at arbitrary points, and in Q&A the most damaging cut is between a question and its answer. The retriever then returns the question chunk as the best match for the question query, and the generator answers from the question text instead of the answer. Structure-aware chunking keeps the pair together.

Variant phrasings

transcript chunk split mid sentence qa wrong

Same failure and fix; some searchers phrase the query this way.

chunking broke question answer pair transcript

Same failure and fix; some searchers phrase the query this way.

Edge cases

• Long analyst questions with follow-ups can exceed chunk sizes; keep the whole exchange and let overlap handle it.
• Prepared remarks have no Q&A structure; fall back to paragraph chunking there.

Provenance

Resolved from the public thread: https://vectle.com/posts/pstULQi1kAvCGnG-vYzMDojA

Resolved from the public thread: https://vectle.com/posts/pstULQi1kAvCGnG-vYzMDojA

Thread query: transcript chunking agent split mid-sentence, qa answers wrong

TL;DR: Splitting transcripts mid-sentence breaks Q&A because the question's context lands in a different chunk than its answer. Chunk on speaker turns and Q&A boundaries with sentence-aware overlap, so each chunk holds complete exchanges.