Data cleaning

Making datasets less noisy to improve quality of translation.

Regular pipeline

Config setting:

  use-opuscleaner: false

Dataset fixing

Some datasets require fixes like detokenization. Dataset and language specific fixes are implemented in https://github.com/mozilla/translations/tree/main/pipeline/clean/fixes. Naming convention:

<dataset_name>.sh for parallel dataset cleaning
<dataset_name>.<lang>.sh for language specific cleaning of parallel or monolingual dataset
/ in dataset name should be replaced with _

Cleaning scripts

Make sure the language is present in clean_parallel script.

Bicleaner

It is recommended to use Bicleaner ML models to filter noisy data. See the bicleaner documentation for more details on how to configure it.

OpusCleaner

Another option is to use an all-in-one cleaning tool OpusCleaner by HPLT project.

Config setting:

  use-opuscleaner: "true"

To enable custom per-dataset filter configs add:

  opuscleaner-mode: "custom"

Custom filter configs

The idea behind OpusCleaner is customizing filter rules for each language pair and dataset to get a training corpus with less noise and train higher quality translation models.

Filtering rules can be tuned in an interactive UI.

Installation

Install the OpusCleaner UI on a server. See the installation instructions in the OpusCleaner readme.

For local usage: run from a poetry shell task opuscleaner. Then go to http://0.0.0.0:8000.

Making filters

Choose a language pair and download the required OPUS datasets. They will correspond to opus_... training datasets in the training pipeline config.

Configure cleaning rules for the datasets in the UI.

Copy JSON files for the produced filters data/train-parts/*.filter.json to pipeline/clean/opuscleaner/configs/<src-lang-code>-<trg-lang-code>/ for langauge pair and dataset specific filters (such filters will also apply to the opposite langauge pair)

or to

pipeline/clean/opuscleaner/configs/ for dataset specific filters that will apply to all language pairs.

Make sure to replace the language codes to the template values <src> and <trg>. See examples in the directory.

Default config

If no custom config was specified for the dataset, the default config template will be used.

Modify if needed. Some rules require specifying source or target language. The <src> and <trg> in the template will be automatically replaced with the trained language pair. The generated default config will be copied to the target dataset cleaning directory.

Running

Enable OpusCleaner in the training pipeline config and run the pipeline as usual. OpusCleaner will replace the default clean-corpus script.

Bicleaner