Papers › Improving Massively Multilingual Neural Machine Translation and Zero-Shot Translation

Improving Massively Multilingual Neural Machine Translation and Zero-Shot Translation

24 Apr 2020ACL 2020 6arXiv:2004.11867archive 2025-07-28

Biao Zhang, Philip Williams, Ivan Titov, Rico Sennrich

Massively multilingual models for neural machine translation (NMT) are theoretically attractive, but often underperform bilingual models and deliver poor zero-shot translations. In this paper, we explore ways to improve them. We argue that multilingual NMT requires stronger modeling capacity to support language pairs with varying typological characteristics, and overcome this bottleneck via language-specific components and deepening NMT architectures. We identify the off-target translation issue (i.e. translating into a wrong target language) as the major source of the inferior zero-shot performance, and propose random online backtranslation to enforce the translation of unseen training language pairs. Experiments on OPUS-100 (a novel multilingual dataset with 100 languages) show that our approach substantially narrows the performance gap with bilingual models in both one-to-many and many-to-many settings, and improves zero-shot performance by ~10 BLEU, approaching conventional pivot-based methods.

PaperPDFConference PDFCodeCode Syntology ran

In Syntology Open this paper in Syntology's Atlas, the map of the papers in Syntology's graph and their citations.

For agents, Syntology's MCP tool lists every function and class Syntology harvested from this paper and whether it ran (how to connect): get_harvested_code_for_paper(arxiv_id="2004.11867")

Code

Syntology Ran 2 of 13 code samples harvested from 1 repository linked to this paper; 11 have no recorded run. Of those that ran: 2 ran · fixture could not drive it.

By repository: official repository: 13 samples from 1 repository, 2 ran. The run record, sample by sample. “Ran” means executed on a synthesized input, not that the code is correct or reproduces the paper.

EdinburghNLP/opus-100-corpus officialmentioned in paper report
bzhangGo/zero officialmentioned in papertf report
YuweiYin/HLT-MT mentioned on GitHubpytorch report

Repository list and official/mentioned flags are the archive's, frozen 2025-07-28. Reachability, where shown, is from one Syntology probe window (2026-09-16 to 2026-09-18); repositories not probed show nothing. GitHub stars are not tracked.

Code Syntology ran Syntology

13 samples harvested; 2 ran; 0 honoured the contract we drafted; 11 have no recorded run. Read from Syntology's graph 2026-09-24; that is when this build read the record, not when the samples ran.

2ran · fixture could not drive it
11unverified

Licence: 0 of the 13 samples are pointer only, meaning Syntology does not serve that copy's text. This page shows no code text for any sample; each one links to its file in the repository.

Harvested from bzhangGo/zero. “Ran” means the sample executed on a synthesized input. It does not mean the output is correct, and nothing here reproduces the paper's results. “Honoured” and “violated” refer to a contract Syntology drafted from the code itself; “our draft was wrong” and “fixture could not drive it” are failures of Syntology's instrument, not of the code.

Each sample ends with its code_sha256, Syntology's identity for that exact code. An agent fetches the stored sample with Syntology's MCP tool get_code(code_sha256="…") (how to connect); click an identity to copy that call.

Repository labels, per sample. official repository: The archive marks this repository official for the paper. named in the paper: The archive records that the paper mentions this repository; it is not marked official. community (archive-listed): In the archive's code links for this paper, not marked official and not recorded as mentioned in the paper. found in paper text by Syntology: Syntology found this repository in the paper's own text; whether it is the authors' implementation is not asserted. community: Not in the archive's code links for this paper; a community repository Syntology harvested. Samples from a repository marked official are listed first. Licence labels name the repository's licence as recorded at harvest. “Pointer only” means Syntology does not serve that copy's text, for one of four reasons: no licence file was found; the licence was not identified; the licence is recorded as permissive but that copy's record is not marked cleared; or the licence is outside the permissive list Syntology serves text under (MIT, Apache-2.0, BSD and similar). Some licences outside that list permit redistribution, such as WTFPL, and GPL-3.0 under its conditions; they are simply not on the list. Hover a licence label for the reason. File links open the file on GitHub at the default branch, which may have changed since the harvest.

combine_heads bzhangGo/zero/models/transformer_l0drop.py official repository ran · fixture could not drive it fingerprinted BSD-3-Clause (permissive) · 9faf4852d7f74a91 · report
split_heads bzhangGo/zero/models/transformer_l0drop.py official repository ran · fixture could not drive it fingerprinted BSD-3-Clause (permissive) · 688a6272dc140cd0 · report
add_timing_signal bzhangGo/zero/models/transformer_l0drop.py official repository unverified BSD-3-Clause (permissive) · 4b52e600cf72c348 · report
attention_bias bzhangGo/zero/models/transformer_l0drop.py official repository unverified BSD-3-Clause (permissive) · b88b2db9eb46e73d · report
decoder bzhangGo/zero/models/transformer_l0drop.py official repository unverified BSD-3-Clause (permissive) · c01bf5a6fe99ddfb · report
dot_attention bzhangGo/zero/models/transformer_l0drop.py official repository unverified BSD-3-Clause (permissive) · b04d0b5aeab65a69 · report
encoder bzhangGo/zero/models/transformer_l0drop.py official repository unverified BSD-3-Clause (permissive) · dd6b86752ec524cd · report
extract_encodes bzhangGo/zero/models/transformer_l0drop.py official repository unverified BSD-3-Clause (permissive) · 5b2126720aede56f · report
ffn_layer bzhangGo/zero/models/transformer_l0drop.py official repository unverified BSD-3-Clause (permissive) · 36e7645b57365d0d · report
layer_norm bzhangGo/zero/models/transformer_l0drop.py official repository unverified BSD-3-Clause (permissive) · 9dcd5100e4896669 · report
linear bzhangGo/zero/models/transformer_l0drop.py official repository unverified BSD-3-Clause (permissive) · c9710c0dc3de38fe · report
residual_fn bzhangGo/zero/models/transformer_l0drop.py official repository unverified BSD-3-Clause (permissive) · a58e7c7393bd5449 · report
train_fn bzhangGo/zero/models/transformer_l0drop.py official repository unverified BSD-3-Clause (permissive) · 81602c4d87412b16 · report

Tasks

Machine TranslationNMTTranslation

Datasets

Introduced by this paper, per the archive.

OPUS-100

Results from the paper archive 2025-07-28

No leaderboard rows for this paper in the archive.

Report a problem or propose a change · a person checks every report against the paper or source before anything changes; decisions are listed on /corrections