{ "schema_version": "1.0.0", "package_id": "W03", "title": "Discovery, Indexing, and Retrieval", "language": "en", "phase": "Observe", "essential_question": "Can the system obtain the source at all?", "research_cutoff": "2026-08-24", "status": "structurally_complete_authored_draft_human_review_and_timed_pilot_pending", "required_artifacts": [ "README.md", "LECTURE_NOTES.md", "SLIDE_SCRIPT.md", "WORKED_CASE.md", "TRANSCRIPT.md", "manifest.json", "validate_package.py" ], "learning_outcomes": [ "Separate discovery, fetching, representation, index membership, retrieval, reranking, context selection, and generation.", "Name a numerator, denominator, unit, conditioning set, and unknown state at each observable candidate-loss boundary.", "Trace an inverted index and reproduce BM25 under a declared tokenizer, corpus, convention, k1, and b.", "Compute Recall@k from declared qrels and distinguish a candidate miss from an ordering error.", "Analyze sparse, supplied opaque, and hybrid runs without inventing a model identity or closed-platform mechanism.", "Write separate bounded conclusions for an open sandbox and a closed surface observation." ], "time_design": { "status": "authoring_budgets_not_observed_delivery_times", "synchronous_seminar_minutes": 90, "synchronous_core_studio_minutes": 75, "asynchronous_core_minutes_min": 190, "asynchronous_core_minutes_max": 200, "transcript_equivalent_minutes_min": 35, "transcript_equivalent_minutes_max": 45, "full_lab_effort_hours": 7, "pilot_state": "not_taught_not_rehearsed_not_timed", "media_state": "no_video_or_audio_recording_exists" }, "local_dependencies": [ { "id": "COURSE-W03", "path": "course-site/app/lib/course-data.ts#W03", "role": "Authoritative current week title, essential question, outcomes, prerequisite, lab link, and open/closed boundary wording.", "boundary": "A curriculum record is not evidence that the lesson has been delivered or effective." }, { "id": "NOTES-APP-F-BM25", "path": "notes-latex/appendices/f-prerequisite-bridges.tex#sec:bridge-bm25", "role": "Notation and conceptual alignment for positive-IDF BM25, dense and hybrid retrieval, and ranking metrics.", "boundary": "The bridge teaches inspectable arithmetic and interpretation; its synthetic examples are not platform results." }, { "id": "LAB-L03", "path": "course-labs/L03_retrieval_reranking_sandbox", "role": "Deterministic offline fixture, code, qrels, runs, metric definitions, stage boundary, and reproducibility route.", "boundary": "Ten CC0 synthetic documents and three authored topics support course exercises only; no external validity or production-system effect is established." }, { "id": "LAB-L03-OPAQUE-RUN", "path": "course-labs/L03_retrieval_reranking_sandbox/data/frozen_dense_run_metadata.json", "role": "Machine-readable ceiling for the supplied opaque score stream.", "boundary": "The model identity is none; the scores must not be attributed to DPR, an embedding model, or a commercial system." } ], "external_sources": [ { "id": "IR-BOOK", "type": "open_textbook", "title": "Introduction to Information Retrieval", "authors": "Christopher D. Manning, Prabhakar Raghavan, and Hinrich Schütze", "url": "https://nlp.stanford.edu/IR-book/", "role": "Classical information-retrieval vocabulary and inverted-index background.", "boundary": "Durable IR foundations do not describe a current generative answer product or establish any GEO intervention effect." }, { "id": "BM25-FOUNDATION", "type": "peer_reviewed_review", "title": "The Probabilistic Relevance Framework: BM25 and Beyond", "authors": "Stephen Robertson and Hugo Zaragoza", "doi": "10.1561/1500000019", "url": "https://doi.org/10.1561/1500000019", "role": "Primary conceptual route for BM25 history, assumptions, and variants.", "boundary": "The package uses one declared implementation convention; the source does not establish a universal parameter choice or production ranking behavior." }, { "id": "DPR", "type": "peer_reviewed_paper", "title": "Dense Passage Retrieval for Open-Domain Question Answering", "authors": "Vladimir Karpukhin et al.", "doi": "10.18653/v1/2020.emnlp-main.550", "url": "https://aclanthology.org/2020.emnlp-main.550/", "role": "Identified example of a dual-encoder dense-retrieval design used to motivate identity fields.", "boundary": "DPR is not executed in L03; no L03 score may be attributed to it, and its paper results are not reproduced here." }, { "id": "RRF", "type": "peer_reviewed_paper", "title": "Reciprocal Rank Fusion Outperforms Condorcet and Individual Rank Learning Methods", "authors": "Gordon V. Cormack, Charles L. A. Clarke, and Stefan Büttcher", "doi": "10.1145/1571941.1572114", "url": "https://doi.org/10.1145/1571941.1572114", "role": "Alternative rank-fusion concept for contrasting rank and raw-score combination.", "boundary": "L03 uses normalized weighted score interpolation, not RRF; the source does not establish that fusion will improve this or any production task." }, { "id": "NDCG", "type": "peer_reviewed_paper", "title": "Cumulated Gain-Based Evaluation of IR Techniques", "authors": "Kalervo Järvelin and Jaana Kekäläinen", "doi": "10.1145/582415.582418", "url": "https://doi.org/10.1145/582415.582418", "role": "Primary route for graded, rank-sensitive evaluation context.", "boundary": "NDCG is a retrieval/ranking metric under judgments and a cutoff; it is not a generated-answer fidelity or user-outcome metric." }, { "id": "RFC-9309", "type": "internet_standard", "title": "Robots Exclusion Protocol", "authors": "M. Koster et al.", "url": "https://www.rfc-editor.org/rfc/rfc9309", "role": "Protocol-scope reference for distinguishing a declared crawler-control signal from later index and retrieval events.", "boundary": "Protocol semantics do not prove crawler compliance, fetch occurrence, indexing, retrieval, citation, or user action on a named service." } ], "fixture_contract": { "corpus_records": 10, "topics": 3, "positive_graded_qrels": 7, "license": "CC0-1.0", "offline": true, "deterministic": true, "bm25": { "idf": "log(1 + (N - n_t + 0.5) / (n_t + 0.5))", "k1": 1.2, "b": 0.75, "tokenizer": "lowercase English-oriented TOKEN_RE from course-labs/shared/geo_lab_core.py" }, "evaluation": { "k": 3, "candidate_depth": 5, "judgment_policy": "unlisted document-topic pairs are treated as gain 0 inside this closed synthetic fixture", "aggregation": "unweighted macro mean over three topics" }, "hybrid_alpha": 0.55, "rerank_weight": 0.25, "opaque_run_identity": "none; scores are authored fixture values" }, "visual_policy": { "external_figure_reuse": false, "external_screenshot_reuse": false, "visuals": "original_instructional_diagram_specifications_only", "required_encodings": [ "label", "shape_or_position", "line_style", "alt_text" ], "license_review_required_before_any_later_external_asset_reuse": true }, "claim_boundary": { "open_sandbox_observable": [ "fixture inputs and rights", "tokenization and index representation", "parameters and commands", "ranked lists and qrels", "Recall@k and NDCG@k under the declared policy", "output and input hashes" ], "closed_platform_unknown_without_separate_evidence": [ "crawl frontier", "index membership", "candidate set", "ranking features", "query rewrite", "context selection cause", "generation influence", "citation mechanism" ], "not_evaluated": [ "public crawling", "production indexing", "named dense model performance", "context packing", "answer generation", "citation correctness", "source absorption", "referral", "user action", "commercial outcome" ] }, "quality_status": { "structural_validator": "passed_2026-08-24", "deterministic_fixture_reproduction": "passed_2026-08-24", "scientific_human_review": "pending", "accessibility_human_review": "pending", "timed_rehearsal": "pending", "classroom_pilot": "pending", "external_peer_review": "pending" } }