Wang 2018 - GLUE - Overview

Summary

GLUE (Wang, Singh, Michael, Hill, Levy and Bowman; ICLR 2019) is a benchmark and online platform for evaluating general natural language understanding: nine English sentence or sentence-pair tasks drawn from existing datasets, scored by a macro-average, with four tasks using privately-held test labels and a hand-built 1,100-example diagnostic set tagged with linguistic phenomena. Baselines show that multi-task training with ELMo and attention scores best (70.0 average) yet low in absolute terms, and the diagnostic set shows models fail on logic.

Overview

Research question. Human language understanding is general; most NLU models are task-specific and struggle out of domain. How do we measure, and encourage, models that share linguistic knowledge across tasks, genres and dataset sizes?

Contribution (four items in the paper).

  1. A suite of nine sentence or sentence-pair NLU tasks built on established datasets, chosen for diversity of genre, size and difficulty (Wang 2018 - Task Suite and Selection Criteria).
  2. An online evaluation platform and leaderboard based mainly on privately-held test data; model-agnostic, so any method producing predictions for all nine tasks can compete (Wang 2018 - Evaluation Protocol and Scoring).
  3. An expert-constructed diagnostic dataset (Wang 2018 - Diagnostic Dataset).
  4. Baselines for major sentence-representation approaches (Wang 2018 - Baselines and Benchmark Results, Wang 2018 - Diagnostic Results and Analysis).

Design philosophy. None of the tasks was created for GLUE: “we rely on pre-existing datasets because they have been implicitly agreed upon by the NLP community as challenging and interesting.” The benchmark rewards parameter sharing by including data-scarce tasks (RTE has 2.5k, WNLI 634 training examples), so that independently trained single-task models are uncompetitive.

Key results.

FindingValue
Best baseline average (test)70.0 (multi-task BiLSTM + attention + ELMo)
Best single-task-trained average66.5 (BiLSTM + attention + ELMo)
Best pre-trained sentence encoder average66.2 (GenSen)
WNLIno model beats the majority-class rate 65.1
Diagnostic set best overall R328 (single-task BiLSTM + attention + ELMo) vs human 80
Hypothesis-only fastText on diagnostic32.7% (SNLI) and 36.4% (MNLI) — near chance, so no annotation artifact

Main Content

Source Map

Paper sectionCovered in
Abstract, 1 Introduction (Table 1)This note; Wang 2018 - Task Suite and Selection Criteria
2 Related Work (SentEval, decaNLP, multi-task learning)Wang 2018 - Task Suite and Selection Criteria
3 Tasks (3.1 single-sentence, 3.2 similarity and paraphrase, 3.3 inference)Wang 2018 - Task Suite and Selection Criteria
3.4 EvaluationWang 2018 - Evaluation Protocol and Scoring
4 Diagnostic Dataset (Tables 2-3, annotation, evaluation, intended use)Wang 2018 - Diagnostic Dataset
5 Baselines (architecture, pre-training, training, sentence-representation models)Wang 2018 - Baselines and Benchmark Results
6 Benchmark Results (Table 4)Wang 2018 - Baselines and Benchmark Results
7 Analysis (Table 5) and ConclusionWang 2018 - Diagnostic Results and Analysis
Appendix A (QNLI construction)Wang 2018 - Task Suite and Selection Criteria
Appendix B (attention, training, sentence models)Wang 2018 - Appendices and Implementation Details
Appendix C (Table 6 dev results)Wang 2018 - Appendices and Implementation Details
Appendix D (website)Wang 2018 - Appendices and Implementation Details
Appendix E (Table 7, diagnostic categories)Wang 2018 - Diagnostic Dataset, Wang 2018 - Appendices and Implementation Details
Referencesnot reproduced

Examples

The GLUE score in one line

For a model with per-task scores, take the unweighted mean of metrics within each multi-metric task, then the unweighted mean over the nine tasks. Check (Table 4, multi-task BiLSTM+Attn+ELMo): CoLA 33.6, SST-2 90.4, MRPC (78.0+84.4)/2=81.2, QQP (84.3+63.1)/2=73.7, STS-B (74.2+72.3)/2=73.25, MNLI (74.1+74.5)/2=74.3, QNLI 79.8, RTE 58.9, WNLI 65.1; mean .

Connections

Relevance to marketing measurement. Two ideas port directly. (1) Private test labels: a benchmark of attribution or MMM methods needs held-out ground truth (experiments) that modelers cannot tune against, matching Experimental Benchmarks for Observational Ad Measurement. (2) Macro-averaging across heterogeneous tasks is a design choice with consequences: it weights a tiny noisy task (WNLI, 146 test examples) equally with a large one, so a single unweighted summary can hide where a method fails.

See Also