- This topic has 4 replies, 4 voices, and was last updated 3 months, 3 weeks ago by
Jeff Bullas.
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Oct 14, 2025 at 2:31 pm #124981
Ian Investor
SpectatorHello — I have a collection of documents (PDFs, notes, and a few webpages) and I’d like a simple way to search them by meaning, not just keywords. I’m not a programmer, so I’m looking for a clear, friendly overview and practical next steps.
What I think the workflow is:
- Create an “embedding” (a numeric summary) for each document or chunk.
- Store those embeddings in a searchable vector database.
- When I type a question, turn it into an embedding, find nearby vectors, and show matching text snippets.
My questions:
- Is that high-level workflow right for a beginner?
- Which user-friendly tools or services work well for non-technical users?
- Any tips on splitting documents, keeping results relevant, or privacy-friendly options?
I’d love short, practical answers or links to simple guides and examples. Please keep explanations non-technical — thanks!
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Oct 14, 2025 at 3:38 pm #124989
aaron
ParticipantQuick point of clarification: embeddings are vector representations of meaning — they enable semantic similarity, not traditional keyword or boolean search. That distinction changes how you design indexing, retrieval, and evaluation.
The problem: you want users to search documents by intent and meaning, not exact words. Keyword search misses synonyms, paraphrases, and context.
Why it matters: semantic search boosts findability, reduces time-to-answer, and surfaces relevant content your users wouldn’t find with keywords. It’s measurable: better relevance means fewer searches per task and higher task completion rates.
Short lesson from experience: start simple: good chunking + consistent metadata + an ANN index = useful results fast. Don’t over-optimize the model before you validate the pipeline.
How to build a simple semantic search — what you need and how to do it
- Gather assets: document corpus (PDFs, docs, webpages), simple metadata (title, date, source).
- Preprocess & chunk: normalize text (lowercase, remove boilerplate), split into 200–800 token chunks with overlap (~20%).
- Create embeddings: pick an embedding model and generate vectors for each chunk.
- Store vectors + metadata: use a vector store/ANN index (Milvus, FAISS, Pinecone, or a simple cosine search for small sets).
- Query flow: convert user query to embedding, retrieve top-N neighbors, re-rank by semantic score + metadata (recency, authority), return passages with source links.
- Feedback loop: capture user clicks and relevance ratings to refine ranking and retrain models or tune weights.
Copy-paste AI prompt (use this to create consistent chunks and summaries):
“You are a document processor. For the following raw text, produce JSON lines where each line has: id, chunk_text (200-600 words), source_title, 1-2 sentence summary, 3 relevant keywords. Ensure chunks do not cut sentences mid-way and include overlap of ~20% with previous chunk.”
What to expect: initial quality will be high for direct queries; edge cases (ambiguous queries, very short text) need tuning. Latency depends on index and hosting — aim for <300ms for embedding lookup if using a managed vector DB.
Metrics to track
- Precision@5 / Recall@5 — relevance of top results
- Mean Reciprocal Rank (MRR)
- Query latency (ms)
- Search-to-resolution (searches per successful task)
- User-rated relevance (1–5)
Common mistakes & fixes
- Mistake: chunks too large — Fix: reduce size to 200–600 words and add overlap.
- Mistake: missing metadata — Fix: attach title/date/source to every vector.
- Mistake: treating embeddings as absolute — Fix: combine semantic score with simple heuristics (recency, authority).
1-week action plan (practical, daily tasks)
- Day 1: Inventory documents + export into plain text.
- Day 2: Write preprocessing script (normalize, remove boilerplate).
- Day 3: Implement chunking; produce sample chunks for 100 documents.
- Day 4: Generate embeddings for sample chunks; load into vector store.
- Day 5: Build a simple query UI that converts query→embedding→top-5 results.
- Day 6: Add metadata-based re-ranking and capture click feedback.
- Day 7: Run evaluation on 50 test queries, calculate Precision@5 and MRR, iterate on chunk size or ranking weights.
Your move.
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Oct 14, 2025 at 4:46 pm #124994
Jeff Bullas
KeymasterNice clarification — you nailed the core point: embeddings capture meaning, not keywords. That shift should drive how you chunk, index and rank results.
Here’s a practical, do-first plan to get a simple semantic search working in a few days — aimed at busy, non-technical builders who want useful results fast.
What you’ll need
- Document corpus exported to plain text (PDFs→text, web pages, docs).
- Basic metadata: title, date, source, doc-id.
- An embedding model (managed or open-source) and a vector store (FAISS, Milvus, Pinecone, or simple cosine for small sets).
- A lightweight app to accept queries and show top-N passages.
Step-by-step (build it now)
- Preprocess: remove headers/footers, normalize whitespace, keep paragraphs.
- Chunk: split into 200–600 word chunks with ~20% overlap; don’t cut sentences mid-way.
- Embed: generate vectors for each chunk and save vector + metadata.
- Index: load vectors into an ANN index for fast nearest-neighbor lookups.
- Query: embed the user query, retrieve top-10 nearest chunks, then re-rank.
- Re-rank: combine semantic score with simple heuristics — recency, exact-match boost, source authority.
- Return: show top-3 passages with source links and a short snippet summary.
Example flow
User asks: “How do I renew my license in 2024?” — system embeds query, retrieves 10 chunks about “license renewal,” boosts chunks from 2024 guidance docs, returns 3 passages: step-by-step, link to official form, and a short AI-generated summary.
Common mistakes & fixes
- Mistake: chunks too big — Fix: shrink to 200–600 words.
- Mistake: no metadata — Fix: attach title/date/source to every vector.
- Mistake: trusting embeddings alone — Fix: combine semantic score with recency/authority boosts.
Quick copy-paste AI prompts
Chunking prompt (paste into your document processor):
“You are a document processor. For the following raw text, produce JSON lines where each line has: id, chunk_text (200-600 words), source_title, 1-2 sentence summary, 3 relevant keywords. Ensure chunks do not cut sentences mid-way and include overlap of ~20% with previous chunk.”
Re-ranker prompt (use after retrieval):
“Given the user query and these candidate passages with metadata, score and return the top 3 passages with a 1-2 sentence rationale for each. Prefer up-to-date, official sources and exact-match phrases.”
Action plan — 7 quick steps
- Day 1: Export documents to text and collect metadata.
- Day 2: Build a preprocessing + chunking script and produce sample chunks.
- Day 3: Generate embeddings for a sample set and load into a vector store.
- Day 4: Build a simple query UI that returns top-5 chunks.
- Day 5: Add re-ranking heuristics and show sources.
- Day 6: Capture click feedback; log relevance scores.
- Day 7: Run 50 test queries, measure Precision@5 and MRR, tweak chunk size or weights.
Start small, measure relevance, then iterate. The quickest win is good chunking + metadata — get that right and everything else follows.
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Oct 14, 2025 at 6:10 pm #125000
Becky Budgeter
SpectatorQuick win: pick one long document, split it into 300–400 word chunks with about 20% overlap, and try a single semantic query to see which chunks feel most relevant — you can do that in under 5 minutes.
What you’ll need
- Plain-text versions of your documents (PDFs → text, copy/paste from webpages).
- Simple metadata for each doc: title, date, source, and an ID.
- An embedding provider or model and a small vector store or even a spreadsheet/calculator for tiny sets.
- A basic way to accept a query and display the top passages (a simple page or a spreadsheet column works to start).
Step-by-step: how to build it and what to expect
- Preprocess: remove headers/footers and obvious boilerplate, keep readable paragraphs. Expect little noise improvement but much better chunking later.
- Chunk: split text into 200–600 word chunks, keep sentence boundaries, and add ~20% overlap so answers that span boundaries aren’t lost. Expect a few extra entries per document but more reliable matches.
- Generate embeddings: for each chunk, create a vector representation (use a managed API or an open model). For small tests you can do a handful manually; for scale, batch this step. Expect each chunk to become a single searchable item.
- Index/store: save vectors with their metadata in a vector store or a simple nearest-neighbor setup. For a few hundred chunks a basic cosine-similarity search is fine; for thousands use an ANN index. Expect much faster lookups with an index.
- Query & retrieve: embed the user query, find top-N similar chunks (start with N=10). You’ll get semantically similar passages, not perfect exact matches — that’s normal.
- Re-rank & return: combine similarity score with simple rules (newer docs, exact phrase boost, trusted sources) and show top 3 passages with their source and a 1–2 line snippet. Expect better relevance than keyword search for synonyms and paraphrases.
What to watch for and quick fixes
- Problem: chunks too big — Fix: shrink to 200–400 words.
- Problem: irrelevant older docs — Fix: add a recency boost in re-ranking.
- Problem: results lack context — Fix: return surrounding paragraph or link to the original doc.
Simple tip: start with 50–100 real queries from your users and use those to tune chunk size and re-ranking weights — small labeled tests pay off fast.
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Oct 14, 2025 at 7:18 pm #125013
Jeff Bullas
KeymasterBuild a “good enough” semantic search this afternoon — then improve it with two tiny tricks that move the needle: smart chunk prefixes and query expansion. You’ll see better matches without adding complex tech.
Context
You’ve got the basics: chunking, embeddings, and a nearest-neighbor lookup. Now let’s make it dependable for real users by tightening how you index, retrieve, and rank — and by adding a dead-simple quality loop.
Do / Don’t (use this as your checklist)
- Do keep chunks short (200–500 words) with ~20% overlap.
- Do add a prefix to each chunk: “Document Title > Section > Subsection” at the top of the chunk text. It massively improves retrieval and user trust.
- Do store basic metadata: title, date, source, doc-id, section, and URL/path.
- Do L2-normalize vectors and use cosine similarity for consistent scoring.
- Do combine semantic score with simple boosts: recency, authoritative sources, and exact-phrase presence.
- Do keep a parent→child map (document → its chunks) so you can show context or group results.
- Don’t mix embeddings from different models in one index.
- Don’t index boilerplate (nav, footers, legal repeats) — it pollutes results.
- Don’t return a chunk without a source title, date, and “open in document.”
- Don’t ship without a tiny relevance log (query, top results, clicked result, rating 1–5).
What you’ll need
- Plain-text versions of documents and simple metadata (title, date, source, doc-id).
- An embedding model and a small vector store (FAISS/Milvus/Pinecone or cosine for tiny sets).
- A lightweight UI that takes a query and shows top passages with sources.
Step-by-step (90-minute build)
- Normalize text: strip headers/footers, fix whitespace, keep paragraphs.
- Prefix chunks: before each chunk’s body, add: “Title > H2 > H3”. This acts like a breadcrumb for both retrieval and users.
- Chunk smart: 200–500 words, ~20% overlap, don’t split sentences. Keep a sequence number per chunk.
- Embed + store: create embeddings, L2-normalize if needed, store vector + chunk_text + metadata (title, date, doc-id, section, url, chunk_no).
- Query-side expansion (high-impact trick): generate 2–3 alternative phrasings of the user’s query (synonyms, common variants). Retrieve for all, then merge and de-duplicate.
- Retrieve top-N: start with N=10. For larger sets, use an ANN index. Compute a final score = 0.8×semantic + 0.2×boosts (recency, authority, exact phrase).
- Return results: show top 3 passages with title, date, 1–2 line snippet, and a link/anchor to the original doc. Offer a “show surrounding paragraph.”
Copy-paste AI prompts (use as-is)
- Chunker with breadcrumbs:“You are a document processor. From the raw text and its outline (title and headings), output JSONL where each line has: id, chunk_text (200–500 words), breadcrumb (Title > H2 > H3), doc_id, source_title, date, url, chunk_no, summary (1–2 sentences), keywords (3–5). Do not cut sentences. Include ~20% overlap with the previous chunk. Prepend the breadcrumb line at the start of chunk_text.”
- Query expansion:“Expand this user query into 3 alternative phrasings that use different common terms and synonyms but keep the same intent. Return as a JSON list of strings. Keep each under 12 words.”
- Re-ranker (LLM-based, optional):“Given the user query and these candidate passages with metadata (title, date, source, exact-phrase flag), return the top 3 with a relevance score (0–100) and a 1–2 sentence rationale. Prefer up-to-date, official sources and direct instructions.”
Worked example
Say you have an HR handbook and policy PDFs. A user asks: “How do I renew my professional license in 2024?”
- Your chunks include a prefix like: “HR Handbook 2024 > Licenses & Compliance > Renewals”.
- Query expansion adds: “license renewal steps 2024”, “renew certificate 2024 process”, “update professional registration 2024”.
- Retrieval pulls 10 candidates. You boost chunks dated 2024 and any with an exact phrase match for “renew” + “license”.
- Top 3 show: steps, required documents, and the renewal deadline, each with title/date and a “open section” link. Latency stays snappy even without heavy re-ranking.
Common mistakes & fast fixes
- Mixed models in one index. Fix: re-embed everything with one chosen model.
- Overlong chunks blur meaning. Fix: target 300–400 words, keep overlap.
- Old answers outrank new ones. Fix: add a simple time decay or +10 score boost if date ≥ current year.
- Repeating boilerplate dominates. Fix: delete footers/nav before chunking; de-duplicate highly similar chunks (cosine ≥ 0.95).
- Users don’t trust results. Fix: always show breadcrumb + date + a short snippet; let them open the surrounding context.
What to expect
- Direct, well-phrased queries perform best immediately.
- Query expansion lifts recall on vague or synonym-heavy queries.
- Breadcrumb prefixes improve both retrieval and user confidence.
- For a few thousand chunks, response time stays well under a second on a modest setup.
Mini evaluation loop (keep it simple)
- Create 50 real queries with a correct-answer snippet id.
- Measure: Precision@5, MRR, and click-through rate on top result.
- Adjust: chunk size, recency boost, exact-phrase weight, and the number of query expansions (usually 2–3 is enough).
3-day action plan
- Day 1: Export text, strip boilerplate, add breadcrumbs, chunk, and embed 1–2 priority documents.
- Day 2: Build retrieval with query expansion, add simple boosts, and return top 3 with sources.
- Day 3: Collect 50 queries, log clicks/ratings, tweak weights, and write a one-page “how to search” tip sheet for users.
Closing thought
Start with the quick win you’ve already proven. Then add the two upgrades — breadcrumbs in chunks and small query expansion — and you’ll get a noticeable jump in relevance without complexity. Ship, watch the logs, and iterate.
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