TREC Deep Learning Track
Overview
The TREC Deep Learning Track is the evaluation campaign that asked what ranking models can do when training labels are abundant rather than scarce. It ran from 2019 through 2023, with the 2023 edition billed as the fifth anniversary and the final one, and it is built on MS MARCO — the track exists because MS MARCO supplies “a large human-generated set of training labels,” on the order of hundreds of thousands of labelled queries, which earlier TREC collections never had.
Within this vault it is the collection most retrieval-evaluation work is measured on, and the one both Benchmarking LLM-based Relevance Judgment Methods and Criteria-Based LLM Relevance Judgments use to test whether an LLM judge can stand in for NIST assessors.
Tasks
Two tasks, each with a full-ranking and a reranking subtask:
- Passage ranking — rank passages from the full collection, or rerank the top 100. The primary focus by 2023.
- Document ranking — rank documents “based on their likelihood of containing a passage relevant to the question.”
Runs submit up to 100 results per query per task.
Scale
The 2019 edition used a corpus of 3.2 million documents and 8.8 million passages, with 367,000 training queries for the document task and 503,000 for the passage task. The later (v2) corpora are considerably larger: 138,364,198 passages (20.3 GB) and 11,959,635 documents (32.3 GB).
Test queries are few and deeply judged rather than many and shallowly judged — 43 reusable test queries per task in 2019, against which 15 groups submitted 75 runs. The 2023 edition released a 700-query test set.
Judgments
NIST assessors apply multi-graded judgments to passages using depth pooling. Document-ranking labels are not assessed independently — they are inferred from the passage judgments.
This is the property that makes the track useful for studying automatic judges: the human labels are graded, pooled, and produced under a documented process, so a proposed LLM judge can be scored both on whether it reproduces individual assessor grades and on whether a leaderboard built from its labels orders the submitted runs the way the human one does. Those two questions have different answers — see Benchmarking LLM-based Relevance Judgment Methods.
Related Datasets
- MS MARCO — the corpora and training labels the track is built on
- LLMJudge — a relevance-judgment challenge collection derived from the track’s TREC 2023 passage task
- TREC-COVID — a different TREC collection, biomedical rather than open-domain web
- BEIR — zero-shot suite that includes MS MARCO and other TREC collections
Related Concepts
- Search Evaluation — the practice this track institutionalizes
- Judgment Lists — what the NIST assessors produce
- NDCG — the metric the track’s system rankings are built from
- LLM as Judge — evaluated against these judgments
- Reranking — the track’s reranking subtask
Related Articles
- Benchmarking LLM-based Relevance Judgment Methods — uses DL-19/20/21 to separate label agreement from system-ranking agreement
- Criteria-Based LLM Relevance Judgments — uses DL-19/20 plus LLMJudge