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Ideas for Google Summer of Code

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Revision as of 16:54, 8 March 2010 by Jimregan (Talk | contribs)

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This is the ideas page for Google Summer of Code, here you can find ideas on interesting projects that would make Apertium more useful for people and improve or expand our functionality. If you have an idea please add it below, if you think you could mentor someone in a particular area — or just have interests or ideas for that, add your name to "Interested parties" using ~~~

The page is intended as an overview of the kind of projects we have in mind. If one of them particularly piques your interest, please come and discuss with us on #apertium on irc.freenode.net, mail the mailing list, or draw attention to yourself in some other way.

Here are some more things you could look at:


Task Difficulty Description Rationale Requirements Interested
Morphology with HFST (and Foma) read more... 3. Medium Modify the Helsinki Finite State Toolkit to work nicely with Apertium (the Apertium stream format, Superblanks etc.). That will involve implementing the tokenise-as-you-analyse algorithm as presented in this paper.[1]. For bonus points, do the same for Foma. The Helsinki Finite State Toolkit provides a drop-in replacement for the Xerox lexc and twol formalisms. There are many morphological analysers/generators "in the wild" written in these formalisms, and they provide substantial features for dealing with morphologically complex languages. C++, Knowledge of FSTs Francis Tyers
Easy dictionary maintenance 2. Hard Write code that simplifies the maintenance of the single-word part of Apertium monolingual and bilingual dictionaries. This involves building an application that parses and reads the open-class (noun, adjective, verb) single-word part of the dictionary amenable to simple, data-base-like treatment, saving the remaining (hard to treat) part of the dictionaries, allows the user to easily add words (together with their inflection paradigms) through a friendly user interface and then combines the extended single-word data with the remaining data into Apertium monolingual and bilingual dictionaries ready to be compiled. Ideas and code from Apertium-dixtools could be useful. Apertium dictionaries are very heterogeneous, but a great part of the development of a language pair consists in adding single words to monolingual and bilingual dictionaries, and, indeed, work on this part of the dictionaries is crucial for coverage and usefulness. Currently, dictionary maintenance is difficult because it involves editing an XML file. This may be slowing down the development of many language pairs. Knowledge of XML, XSLT and one programming language that allows XML processing and easy writing of a user interface Mikel L. Forcada, Jimregan 15:54, 8 March 2010 (UTC)
Discontiguous multiwords read more... 3. Medium The task will be to develop, or adapt a module to deal with these kind of contiguous multiword expressions, for example, taking 'liggja ekki fyrir' and reordering it as 'liggja# fyrir ekki'. In many languages, such as English, Norwegian and Icelandic, there are discontiguous multiwords, e.g. phrasal verbs, that we cannot easily support. For example 'liggja ekki fyrir' in Icelandic should be translated in English as 'to be not clear', but we cannot have 'liggja fyrir' as a traditional multiword because of the extra 'adverb', or it could even be a whole NP. C++, Knowledge of FSTs Francis Tyers
Flag diacritics in lttoolbox read more... 2. Hard Adapt lttoolbox to elegantly use flag diacritics. This will involve designing some changes to our XML dictionary format (see lttoolbox, and implementing the associated changes in the FST compiling processing code. C++, XML, Knowledge of FSTs Francis Tyers
Accent and diacritic
3. Medium Create an optional module to restore diacritics and accents on input text, and integrate it into the Apertium pipeline. Many languages use diacritics and accents in normal writing, and Apertium is designed to use these, however in some places, especially for example. instant messaging, irc, searching in the web etc. these are often not used or untyped. This causes problems as for the engine, traduccion is not the same as traducción. C, C++, XML, familiarity with linguistic issues
Porting read more... 3. Medium Port Apertium to Windows complete with nice installers and all that jazz. Apertium currently compiles on Windows (see Apertium on Windows) While we all might use GNU/Linux, there are a lot of people out there who don't, some of them use Microsoft's Windows. It would be nice for these people to be able use Apertium too. C++, autotools, experience in programming on Windows.
Tree-based transfer read more... 1. Very hard Create a new XML-based transfer language for tree-based transfer and a prototype implementation, and transfer rules for an existing language pair. Apertium currently works on finite-state chunking, which works well, but is problematic for less-closely related languages and for getting the final few percent in closely-related languages. A tree-based transfer would allow us to work on real syntactic constituents, and probably simplify many existing pairs. There are some existing non-free implementations.[2] [3] XML, Knowledge of parsing, implementation language largely free.
Interfaces 4. Entry level Create plugins or extensions for popular free software applications to include support for translation using Apertium. We'd expect at least Firefox and Evolution (or Thunderbird), but to start with something more easy we have half-finished plugins for Pidgin and XChat that could use some love. The more the better! Further ideas on plugins page Apertium currently runs as a stand alone translator. It would be great if it was integrated in other free software applications. For example so instead of copy/pasting text out of your email, you could just click a button and have it translated in place. This should use a local installation with optional fallback to the webservice. Depends on the application chosen, but probably Java, C, C++, Python or Perl.
Linguistically-driven filtering of the bilingual phrases used to infer shallow-transfer rules 3. Medium Re-working apertium-transfer-training-tools to filter the set of bilingual phrases automatically obtained from a word-aligned sentence pair by using linguistic criteria. Apertium-transfer-training-tools is a cool piece of software that generates shallow-transfer rules from aligned parallel corpora. It could greatly speed up the creation of new language pairs by generating rules that would otherwise have to be written by human linguists C++, general knowledge of GIZA++, Perl considered a plus.
Use of context-dependent lexicalized categories in the inference of shallow-transfer rules 2. Hard Re-working apertium-transfer-training-tools to use context-dependent lexicalized categories in the inference of shallow-transfer rules. Apertium-transfer-training-tools generates shallow-transfer rules from aligned parallel corpora. It uses an small set of lexicalized categories, categories that are usually involved in lexical changes, such as prepositions, pronouns or auxiliary verbs. Lexicalized categories differentiate from the rest of categories because their lemmas are taken into account in the generation of rules. C++, general knowledge of GIZA++, XML.
Automated lexical
2. Hard Writing a C++ wrapper around Markus Forsberg's Extract tool (version 2.0) as a library to allow it to be used with Apertium paradigms and TSX files / Constraint grammars as input into its paradigms and constraints. One of the things that takes a lot of time when creating a new language pair is constructing the monodices. The extract tool can greatly reduce the time this takes by matching lemmas to paradigms based on distribution in a corpus. Haskell, C++, XML
Improve integration of
lttoolbox in libvoikko
3. Medium Dictionaries from lttoolbox can now be used for spellchecking directly with libvoikko (see Spell checking). The idea of this project is to improve the integration. Fix bugs, look at ways of codifying "standard"/"sub-standard" forms in our dictionaries. Spell checkers can be useful, for languages other than English moreso. They are one of the "must have" items of language technology. If we can re-use Apertium data for this purpose it will help both the project (by making creating new language pairs more rewarding) and the language communities (by making more useful software). XML, C++. Francis Tyers
Complex multiwords 2. Hard Write a bidirectional module for specifying complex multiword units, for example dirección general and zračna luka. See Multiwords for more information. Although in the Romance languages it is not a big problem, as soon as you start to get to languages with cases (e.g. Serbo-Croatian, Slovenian, German, etc.) the problem comes that you can't define a multiword of adj nom because the adjective has a lot of inflection. C, C++, XML
Adopt a
language pair
4. Entry level Take on an orphaned language pair, and bring it up to release quality results. What this quality will be will depend on the language pair adopted, and will need to be discussed with the prospective mentor. This will involve writing linguistic data (including morphological rules and transfer rules — which are specified in a declarative language) Apertium has a few pairs of languages (e.g. sh-mk, en-af, ga-gd, etc...) that are orphaned, they don't have active maintainers. A lot of these pairs have a lot of work already put in, just need another few months to get them to release quality. See also Incubator XML, a scripting language (Python, Perl), good knowledge of the language pair adopted. Francis Tyers
3. Medium Make a post-edition tool to speed up revision of Apertium translations. It would likely include at least support for spelling and grammar checking, along with defining user-specified rules for fixing translations (search and replace, etc.). This tool can reuse an existing grammar checker such as LanguageTool. After translating with Apertium revision work has to be done to consider a translation as an "adequate" translation. An intelligent post-edition environment will help doing this task. In this environment some typical mistakes in the translation process that can be automatically detected (for example unknown words and homographs) could be highlighted to be taken in consideration while doing post-edition. Some typical mistakes could also be defined to advise the post-editor to check them. XML, PHP, Python, C, C++, whichever programming language.
Detect 'hidden' unknown words 3. Medium The part-of-speech tagger of Apertium can be modified to work out the likelihood of each 'tag' in a certain context, this can be used to detect missing entries in the dictionary. Apertium dictionaries may have incomplete entries, that is, surface forms (lexical units as they appear in running texts) for which the dictionary does not provided all the possible lexical forms (consisting of lemma, part-of-speech and morphological inflection information). As those surface form for which there is at least one lexical form cannot be considered unknown words, it is difficult to know whether all lexical forms for a given surface form have been included in the dictionaries or not. This feature will detect 'possible' missing lexical forms for those surface forms in the dictionaries. C++ if you plan to modify the part-of-speech tagger; whatever if rewriting it from scratch.
Format filters 4. Entry level Making apertium capable of dealing with more different formats, for the minimum: files marked up with LaTeX and Wiki. Apertium can currently deal with texts in plain-text, RTF, HTML and ODT formats by means of a format definition file. It should be easy to use the same language to define filters for other formats. Apertium format definition language and/or scripting languages.
Language independent
target-language tagger training
2. Hard Modify apertium-tagger-training-tools so that it does not need the segmentation provided by the transfer rules in order to score translations, and to prune the k-best list of possible translations at run-time for efficiency apertium-tagger-training-tools is a program for doing target language tagger training. This means that it tunes the parameters of an HMM model based on the quality of the translations through the whole system. At the moment this relies on the segmentation of the input by the transfer rules, and also runs all the possible translations (undisambiguated). It would be good to be able to run it without having this segmentation. This task would also require switching the default perl-based language model to either IRSTLM or RandLM (or both!). C++
vocabulary assistant
4. Entry level Extend Geriaoueg so that it works more reliably with broken HTML and with any given language pair. Geriaoueg is a program that provides "popup" vocabulary assistance, something like BBC Vocab or Lingro. Currently it only works with Breton--French, Welsh--English and Spanish--Breton. This task would be to develop it to work with any language in our SVN and fix problems with processing and displaying non-standard HTML. PHP, C++, XML Francis Tyers
Bytecode for transfer 2. Hard Adapt transfer to use bytecode instead of tree walking. Apertium is pretty fast, but it could be faster, and the transfer is dominating the CPU usage. This task would be write a compiler and interpreter for Apertium transfer rules into the format of an an off-the-shelf bytecode engine (e.g. Java, v8, kjs, ...). If Java bytecode was chosen this might eventually make Apertium run on J2ME devices. See also: Bytecode for transfer C++ and for the bytecode Java or Javascript


  1. Alicia Garrido-Alenda, Mikel L. Forcada, Rafael C. Carrasco (2002) Incremental construction and maintenance of morphological analysers based on augmented letter transducers
  2. Koichi Takeda "Pattern-Based Context-Free Grammars for Machine Translation"
  3. Gábor PRÓSZÉKY and László TIHANYI "MetaMorpho: A Pattern-Based Machine Translation System"

Further reading

Accent and diacritic restoration
Automated lexical extraction
Support for agglutinative languages
Transfer rule learning
  • Sánchez-Martínez, F. and Forcada, M.L. (2007) "Automatic induction of shallow-transfer rules for open-source machine translation", in Proceedings of TMI 2007, pp.181-190 (paper, poster)
Target-language tagger training
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