World Knowledge: TriviaQA, NQ & SQuAD
Master world knowledge benchmarks: TriviaQA, Natural Questions, SQuAD evaluation, and knowledge-grounded AI systems.
What is a world knowledge benchmark?
A world knowledge benchmark is a versioned question set, evidence contract, answer format, and scoring rule used to measure whether a system can find and return factual information. Some tests ask a model to recall a fact, some provide or retrieve documents, and some require the system to abstain when the evidence does not contain an answer.
In plain language, these benchmarks are different kinds of open-book and closed-book exams. They matter because a correct-looking answer can come from memorization, successful retrieval, careful reading, or luck. Those paths fail for different reasons.
The core invariant is match the benchmark's evidence contract to the product claim. A passage-reading score does not prove broad factual recall, and an end-to-end retrieval score does not isolate reader quality.
This lesson builds on evaluation benchmarks. Review that lesson first if frozen protocols, holdouts, contamination, or slice reporting are unfamiliar.
95K
TriviaQA pairs
Question-answer pairs with independently collected evidence
307,373
NQ training examples
Real search queries paired with annotated Wikipedia pages
50K+
SQuAD 2.0 no-answer items
Plausible questions whose supplied passage lacks the answer
1 contract
Comparable evidence
Freeze data, prompt, retrieval, answer policy, and scorer
Separate the question from the evidence contract
A benchmark name alone does not define the experiment. Record what the system receives, what it may retrieve, which answer forms count, and when abstention is correct.
Model memory
Closed-book recall
The model receives a question without supporting documents. A correct answer tests behavior under that prompt, but it does not prove freshness, provenance, or reliable retrieval.
Retrieve then read
Open-domain QA
The system searches a declared corpus before answering. Measure retrieval coverage and reader correctness separately so one stage cannot hide the other.
Read supplied context
Passage QA
The question arrives with a bounded passage. The task tests extraction and no-answer behavior inside that context, not broad world coverage.
Freeze the run manifest
- Data identity: source, immutable revision, split, question IDs, evidence documents, exclusions, and deduplication result.
- System contract: model and index revisions, prompt, retrieval depth, reranker, decoding settings, and tool access.
- Answer contract: accepted aliases, normalization, citation requirement, abstention token, and maximum answer length.
- Report contract: exact match, token F1, retrieval recall, no-answer metrics, slices, uncertainty, cost, and latency.
Do not blend closed-book, retrieved-evidence, and supplied-passage results into one unexplained world-knowledge score. The denominator and failure path must remain visible.
Build a portfolio that matches the product claim
A support assistant, an internal-document reader, and a closed-book trivia feature need different evidence. Use the lab to choose a product claim, sample budget, and evidence mode. The benchmark allocation, critical-trait coverage, blind spots, and release status update together.
Make the benchmark portfolio earn the claim
Choose the product behavior, sample depth, and evidence mode. Coverage and the release consequence update from the same contract.
Use each benchmark for the decision it represents
TriviaQA tests questions against independently gathered evidence
The original TriviaQA release contains more than 650,000 question-answer-evidence triples built from about 95,000 question-answer pairs. Questions came from trivia enthusiasts, while web and Wikipedia evidence was gathered independently. That separation creates lexical and syntactic gaps between a question and its evidence.
- Score against all documented answer aliases rather than one literal string.
- Keep Wikipedia, web, verified, and unfiltered variants distinct.
- For retrieval experiments, report whether an accepted answer appears in the retrieved set before scoring the reader.
- Treat evidence that merely contains an answer string as distant supervision, not proof that every document supports the answer correctly.
Natural Questions tests real search behavior
Natural Questions uses anonymized, aggregated queries issued to Google Search. Annotators receive a Wikipedia page from the search results and may mark a long answer, a short answer, yes or no, or no supported answer.
- Preserve the difference between long-answer selection and short-answer extraction.
- Keep null answers in the denominator; filtering them creates an easier task.
- Slice by answer type, query form, document length, and evidence position.
- Do not call a reader-only experiment end-to-end search unless retrieval is actually part of the evaluated system.
SQuAD 2.0 tests extraction and abstention inside one passage
SQuAD 2.0 combines the answerable SQuAD 1.1 questions with more than 50,000 adversarially written unanswerable questions. The unanswerable questions resemble answerable ones, so a reader must compare its best span score with a no-answer score.
- Tune the no-answer threshold on a development split, then freeze it before test evaluation.
- Report answerable and unanswerable subsets beside the combined score.
- Retain exact match and token F1 because partial span overlap and exact extraction answer different questions.
- Do not use SQuAD alone to claim current knowledge, retrieval quality, or open-domain coverage.
Read the metrics as a failure map
Strict answer contract
Exact match
After declared normalization, the prediction must equal at least one accepted alias. It is reproducible but can reject an otherwise useful answer when the alias set or extractor is incomplete.
Partial overlap
Token F1
Precision and recall over normalized tokens give partial credit to overlapping spans. F1 does not establish that a longer generated answer is factually consistent.
Evidence coverage
Retrieval recall
Measure whether at least one acceptable evidence unit appears in the retrieved top-k set. A reader cannot extract evidence that retrieval never supplied.
Selective answering
No-answer behavior
Track correct abstentions and unsupported answers separately. A system can improve aggregate accuracy by refusing too often while becoming less useful.
Keep the arithmetic explicit
For answerable questions in a simplified retrieval pipeline:
supported correct rate = retrieval recall x reader correctness given retrieved evidence
If retrieval recall is 80% and reader correctness is 90%, at most 72% of answerable items are supported correct under those assumptions. Improving only the reader cannot recover the 20% of questions whose evidence never arrived.
Diagnose the stage that loses the answer
The next lab partitions one evaluation set into supported correct answers, retrieval misses, reader errors, correct abstentions, and unsupported answers. Change the answerable share and each stage quality. Every question remains in exactly one outcome bucket, so the largest failure source identifies the next experiment.
Find the stage that loses the answer
Every question flows into one auditable outcome. Challenge retrieval, reading, or abstention and watch the release gate and next investment move.
Implement scoring and attribution as auditable boundaries
The first example normalizes only documented surface differences, scores against all aliases, and treats an empty prediction as abstention only for an unanswerable item.
The second example assigns every evaluated question to one pipeline outcome. Production records should also retain the query, retrieved document IDs, corpus revision, prompt, raw answer, scorer revision, and latency.
Test the evaluator itself
- Add fixtures for aliases, punctuation, articles, empty answers, Unicode, duplicate tokens, and malformed records.
- Fail closed when an answerable item has no accepted aliases or when required stage evidence is missing.
- Keep scorer changes versioned and rerun old predictions before comparing reports.
- Manually review a bounded sample of exact matches, partial matches, abstentions, and retrieval misses.
Operate the benchmark as a measurement system
1 Scope
Freeze product-shaped slices
Sample stable facts, time-sensitive facts, ambiguous queries, answerable questions, and unsupported questions in proportions that reflect the declared claim.
2 Measure
Run one traceable pipeline
Persist retrieval and reader inputs, outputs, versions, timings, and policy decisions for every item without silently retrying failures.
3 Diagnose
Attribute before tuning
Separate corpus gaps, retrieval misses, reader errors, alias failures, unsupported answers, and justified abstentions before changing the system.
4 Release
Gate with multiple signals
Require critical-slice floors, retrieval coverage, answer quality, no-answer behavior, cost, latency, and contamination checks to pass together.
Minimum production report
- Overall exact match and token F1 with the denominator and uncertainty interval.
- Retrieval recall at each declared
k, plus oracle-reader performance when gold evidence is available. - Answerable and unanswerable performance, including unsupported-answer and over-refusal rates.
- Results by benchmark, source, question type, temporal sensitivity, answer length, and critical product slice.
- Corpus, index, model, prompt, and scorer revisions with tokens, latency, and cost.
An aggregate gain is not a release decision. A support system can improve overall while regressing on current facts, unsupported questions, or a high-consequence domain.
Know what these benchmarks cannot prove
- Public benchmark items may overlap with training, prompt libraries, retrieval corpora, or repeated development runs.
- Wikipedia-centered evidence does not represent every language, culture, domain, or current event.
- Exact match and F1 do not verify every claim in a long generated answer or the quality of a citation.
- A fresh corpus does not guarantee fresh answers if retrieval misses the relevant document or generation ignores it.
- A high no-answer score can hide blanket refusal unless answer coverage and usefulness are reported.
- Static benchmark success does not replace private product cases, red-team questions, monitoring, or incident review.
For a release claim, combine public benchmarks with protected product-shaped holdouts, time-stamped freshness cases, citation verification, and operational monitoring.
Ground the protocol in the original releases
- The TriviaQA paper defines the question-answer-evidence construction and the original dataset variants.
- The Natural Questions publication documents real search queries, long and short annotations, null cases, and public split sizes.
- The SQuAD 2.0 paper explains the adversarial unanswerable-question design and the need to abstain.
Use the official release's schema, split, scorer, and license as the baseline. Add product diagnostics as separately named evidence rather than silently redefining the public score.