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Core12–20 hours

Evidence-first Knowledge Assistant

Build a RAG assistant that answers only from verified evidence, shows citations, and measures retrieval quality.

ingestionchunkinghybrid retrievalrerankingcitationsRAG evaluation

Scenario

Task

A team needs an assistant for internal policies. The system must not invent answers, must expose its sources, and must abstain when the evidence is insufficient.

Step-by-step execution

1. Prepare the corpus

Outcome: Documents have owner, version, and access metadata.

Tasks

  • Select 20–50 documents
  • Clean the structure
  • Add metadata
  • Store the source URI

Checks

  • Every chunk has a source
  • Versioning is reproducible

2. Configure retrieval

Outcome: Relevant passages consistently reach the top-k.

Tasks

  • Compare chunk sizes
  • Add lexical + vector search
  • Configure reranking
  • Add an ACL filter

Checks

  • A test query set exists
  • ACL is covered by negative tests

3. Build the evidence contract

Outcome: The model cannot hide missing evidence.

Tasks

  • Define the citation schema
  • Add abstention
  • Validate source IDs
  • Reject unsupported claims

Checks

  • Every claim has a citation or abstention
  • An unknown source ID blocks the answer

4. Run evaluation

Outcome: Retrieval and generation quality are measured separately.

Tasks

  • Create a golden set
  • Calculate recall@k
  • Evaluate citation correctness
  • Build a failure taxonomy

Checks

  • A baseline exists
  • A regression threshold is recorded

Acceptance criteria

  • Every citation opens a real source
  • ACL prevents data leakage
  • Weak evidence triggers abstention
  • The evaluation report contains a baseline and failure examples

Assessment rubric

How the result is assessed

Passing score: 70/100 · Distinction: 90/100

Corpus and provenance

Documents, chunks, metadata, versions, and source URIs are reproducible.

20 points

Insufficient

Sources lack version or owner metadata, or chunks lose provenance.

Competent

Every chunk has source, metadata, and version.

Strong

Freshness policy, lineage, and change control are implemented.

Evidence required

  • ✓ Link to code or artifact
  • ✓ Short README explaining decisions
  • ✓ Test output or runtime evidence
  • ✓ Example document and its chunks

Retrieval quality

Hybrid retrieval, filters, and reranking are measured on a query set.

30 points

Insufficient

There is no test set or retrieval is judged subjectively.

Competent

A baseline, query set, and measurable top-k exist.

Strong

Multiple strategies are compared with a regression threshold and failure taxonomy.

Evidence required

  • ✓ Link to code or artifact
  • ✓ Short README explaining decisions
  • ✓ Test output or runtime evidence
  • ✓ Recall@k or an equivalent retrieval metric

Grounding and citations

Claims are supported by evidence, and missing evidence causes abstention.

30 points

Insufficient

The model can answer without evidence or citations do not open the source.

Competent

Unsupported claims are blocked and citations are valid.

Strong

Groundedness and citation correctness are measured automatically.

Evidence required

  • ✓ Link to code or artifact
  • ✓ Short README explaining decisions
  • ✓ Test output or runtime evidence
  • ✓ Examples of correct citation and abstention

Access control and security

ACL is applied during retrieval and verified with negative tests.

20 points

Insufficient

Filtering happens after retrieval or leakage remains possible.

Competent

ACL is applied to search and covered by negative tests.

Strong

Tenant isolation, audit logging, and policy tests are implemented.

Evidence required

  • ✓ Link to code or artifact
  • ✓ Short README explaining decisions
  • ✓ Test output or runtime evidence
  • ✓ Negative ACL test

Materials before execution