Module 02 Knowledge Check
5 questions. Pass mark 4 out of 5. Answer every question before checking the answer key below, then retry after reading the feedback.
1. Why does chunk size matter so much?
- A. Storage cost
- B. Too small loses context; too large dilutes the match and wastes the context window
- C. It changes the model
- D. It only affects speed
2. A chunk that begins mid-sentence with 'This must be approved by the regional head' is dangerous because…
- A. It is too short
- B. 'This' has no referent - the chunk is unusable without its context
- C. It contains a policy
- D. It has no numbers
3. What is metadata used for in a retrieval system?
- A. Decoration
- B. Filtering, permissioning, freshness checks, and citation back to the source
- C. Making embeddings smaller
- D. Nothing
4. Permissions must be enforced at retrieval time because…
- A. It is faster
- B. If a restricted chunk enters the context, the model may quote it regardless of instructions
- C. Embeddings are encrypted
- D. Users cannot ask hard questions
5. Overlapping chunks are commonly used to…
- A. Increase index size deliberately
- B. Reduce the chance that an answer is split across a chunk boundary
- C. Improve embedding maths
- D. Satisfy licensing
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Answer Key and Explanations
Check these only after attempting every question.
1. B - Too small loses context; too large dilutes the match and wastes the context window
Chunking is a trade-off between precision of match and sufficiency of context. Both failure directions produce wrong answers.
2. B - 'This' has no referent - the chunk is unusable without its context
Dangling references are a classic chunking bug: the text retrieves well but means something different in isolation.
3. B - Filtering, permissioning, freshness checks, and citation back to the source
Without metadata you cannot restrict by audience, prefer recent documents, or tell the user where an answer came from.
4. B - If a restricted chunk enters the context, the model may quote it regardless of instructions
A prompt instruction is not an access control. Filter before retrieval, not after generation.
5. B - Reduce the chance that an answer is split across a chunk boundary
Overlap trades storage for a lower risk of losing the exact sentence that answers the question.
Practical Check
Apply this module to your own work: complete the module activity for *Documents, Chunks, Metadata, and Permissions*, then write one sentence naming what your result shows and one naming what it does not.
Strong Answer Pattern
A strong answer names the task, the evidence used, the check performed, and the remaining limitation. It avoids "proved", "guaranteed", or "always" unless the evidence genuinely supports it.