Strata
A university-hosted research workspace that turns a doctoral student's papers into a map of claims and evidence.
Automate the early stages. Keep the judgment.
Collecting sources, extracting content, organizing it and finding how papers relate is repetitive work. Strata does it; the researcher keeps every scientific decision and the standard methodology.
- Not a new LLMA knowledge layer on top of existing models, built on published RAG 8 and GraphRAG 10 methods.
- Graph, not chatPapers are split into meaningful units and linked in a multi-layer semantic graph.
- Small contextA hybrid index passes only relevant passages to the model, so library size stops mattering.
- On campusThe model is replaceable and can run on university servers or a private cloud the university controls.
The literature doubles every 17 years.
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Much of that time goes to repetitive work: collecting, first-pass screening, data extraction and comparing findings 26. A doctoral student usually does it across disconnected tools: a browser and publisher sites, a reference manager, a note-taking app and, lately, a chatbot. None of them keeps the relationships between the findings of different papers.
Local evidence: interviews with a few PhD students or a short survey on time spent on literature review.Fluent, confident, and often unsourced.
Chatbots are built for conversation, not for working on a specific library under a scientific procedure. The weakness is not the model. It is the missing data, retrieval and procedure layers around it.
All six weaknesses, with evidence
- Fabricated references. 55% of GPT-3.5 and 18% of GPT-4 citations were fabricated in one test 3; hallucination is a known property of language models 4. Strata answers only from registered sources and links every claim to a passage.
- Limited context. Of models claiming 32K tokens or more, only about half hold up at that length 6. Strata keeps an external index and sends only relevant passages.
- Lost in the middle. Accuracy drops when key information sits mid-input 5. Strata keeps the context short and focused.
- No structured memory. Relations between concepts are not stored 9, so questions like "where is the gap?" get weak answers 10. Strata keeps a multi-layer graph.
- No procedure. No inclusion criteria, decision log or PRISMA flow 7. Strata builds them in.
- Data leaves the university. Raw data and drafts cannot be used. Strata can run inside the university boundary. Reference to a university data policy or research-ethics guideline.
Both answers were written for this page. The left one reproduces failure patterns documented in 3, 5 and 6, and its citation is deliberately invented. The right one shows the answer format Strata is designed to produce; its citations point to this paper's real reference list. Tap a citation chip to see the source.
The machine suggests. The researcher decides.
Six layers. The model is one of them.
This paper's own library, as a graph.
The 30 references below, split into findings, concepts and claims, the way Strata would. Hand-built for this page; findings are paraphrased. Drag to rotate, pinch or scroll to zoom, tap a node.
Four cuts turn a PDF into evidence.
The approach is close to GraphRAG 10 and LightRAG 24, with a schema designed for the scientific literature. Every unit stays linked to its source sentence.
"What was the sample size?"
Precise questions"Who disagrees with this?"
Comparison"Summarize the field."
Paragraph to library, like RAPTOR 11Three searches, fused, then a short context.
Keyword search (BM25) 17 catches exact terms. Dense vectors 18 on an HNSW 19 or FAISS 28 index catch meaning. Graph traversal catches related evidence whose words look nothing like the question 10,24. Reciprocal Rank Fusion merges them 20.
Do long-context models make retrieval unnecessary?
Input size depends on k, not on your library.
N papers of average length L tokens, k retrieved passages of c tokens, q tokens of question and instructions. As N grows, full text grows linearly; retrieval stays flat.
A structural argument, not a measurement. L, k and c (500 tokens) are assumptions you can change. Answer quality depends on retrieval quality and must be measured with standard RAG metrics 29.
The model is a part, not the product.
We train no new model. Knowledge lives in the graph and index, so it updates without retraining and every answer shows its source 8. Swapping the model never means rebuilding the graph.
Commercial API
Early stages on published papers. Fastest start; only retrieved passages leave.
Private cloud
Semi-sensitive data and research groups, with open-weight models such as Llama 3 22 or Qwen2.5 30.
University servers
Raw data, interviews, unpublished drafts, served efficiently with engines such as vLLM 21.
Access to papers and copyright
Strata has no direct access to publisher databases and does not harvest publisher content in bulk. The researcher downloads each paper with their own legal access, and the browser extension registers it as a source with its metadata (DOI, title, authors, journal). Each library is limited to its owner or group.
Legal review of major publishers' terms (Elsevier, Springer, Wiley) on AI text processing, and the host university's data policy.Each tool solves a slice.
Strata's difference is bringing the slices together on the researcher's own library, under university-controlled deployment.
Every claim here is a hypothesis.
- Extraction makes mistakes. Retrieval reduces hallucination but does not remove it 4,9, which is why approval is part of the design.
- PDF conversion (equations, tables, scans) depends on how the paper is built.
- Strata only sees papers the researcher adds. Search completeness stays their responsibility.
- On-campus models may be weaker than commercial ones. The trade-off must be measured.
Prototype
Extension, processing, hybrid index, cited answers.
Graph
Semantic graph and technical evaluation.
Pilot
A group of PhD students and a user study.
On campus
University infrastructure, sensitive data.
Figures from references 1 to 3 were checked against the papers. Page and volume details of the others should be reconciled in a reference manager before publication.
Host the first pilot.
We are looking for doctoral programs and research groups.