Morphological Disambiguation

Task Definition

Morphological disambiguation is the problem of selecting accurate morphological parse of a word given its possible parses. These parses are generated by a morphological analyzer. In morphologically rich languages like Turkish, the number of possible parses for a given word is generally more than one. Each parse is considered as a different interpretation of a single word. Each interpretation consists of a root word and sequence of inflectional and derivational suffixes. The following table illustrates different interpretations of the word ‘‘üzerine’’.

üzer+Noun+A3sg+P3sg+Dat
üzer+Noun+A3sg+P2sg+Dat
üz+Verb+Pos+Aor+^DB+Adj+Zero+^DB+Noun+Zero+A3sg+P3sg+Dat
üz+Verb+Pos+Aor+^DB+Adj+Zero+^DB+Noun+Zero+A3sg+P2sg+Dat

As seen above, the first two parses share the same root but different suffix sequences. Similarly, the last two parses also share the same root, however sequence of morphemes are different. Given a parse such as

üz+Verb+Pos+Aor+^DB+Adj+Zero+^DB+Noun+Zero+A3sg+P3sg+Dat

each item is separated by ‘‘+’’ is a morphological feature such as Pos or Aor. Inflectional groups are identified as sequence of morphological features separated by derivational boundaries ^DB. The sequence of inflectional groups forms the term tag. Root word plus tag is named as word form. So, a word form is defined as follows:

IGroot+IG₁+^DB+IG₂+^DB+...+^DB+IG_n

Then the morphological disambiguation problem can be defined as follows: For a given sentence represented by a sequence of words W = w₁ⁿ = w₁, w₂, ..., w_n, determine the sequence of parses T = t₁ⁿ = t₁, t₂, ..., t_n; where t_i represents the correct parse of the word w_i.

Data Annotation

Preparation

1. Collect a set of sentences to annotate.
2. Each sentence in the collection must be named as xxxx.yyyyy in increasing order. For example, the first sentence to be annotated will be 0001.train, the second 0002.train, etc.
3. Put the sentences in the same folder such as Turkish-Phrase.
4. Build the Java project and put the generated sentence-morphological-analyzer.jar file into another folder such as Program.
5. Put Turkish-Phrase and Program folders into a parent folder.

Annotation

1. Open sentence-morphological-analyzer.jar file.
2. Wait until the data load message is displayed.
3. Click Open button in the Project menu.
4. Choose a file for annotation from the folder Turkish-Phrase.
5. For each word in the sentence, click the word, and choose correct morphological analysis for that word.
6. Click one of the next buttons to go to other files.

Classification DataSet Generation

After annotating sentences, you can use DataGenerator package to generate classification dataset for the Morphological Disambiguation task.

Generation of ML Models

After generating the classification dataset as above, one can use the Classification package to generate machine learning models for the Morphological Disambiguation task.

Simple Web Interface

Link 1 Link 2

Annotated Datasets

Framenet & Tourism

Atis & Gb & Pud & Imst & Boun

Kenet

Penn-Treebank

Video Lectures

For Developers

You can also see Java, Python, Cython, Js, C, Swift, Php, or C# repository.

Requirements

• C++ Compiler
• Git

CPP

To check if you have compatible C++ Compiler installed,

• Open CLion IDE
• Preferences >Build,Execution,Deployment > Toolchain

Git

Install the latest version of Git.

Download Code

In order to work on code, create a fork from GitHub page. Use Git for cloning the code to your local or below line for Ubuntu:

git clone <your-fork-git-link>

A directory called TurkishMorphologicalDisambiguation-CPP will be created. Or you can use below link for exploring the code:

git clone https://github.com/starlangsoftware/TurkishMorphologicalDisambiguation-CPP.git

Open project with CLion IDE

To import projects from Git with version control:

• Open CLion IDE , select Get From Version Control.

• In the Import window, click URL tab and paste github URL.

• Click open as Project.

Result: The imported project is listed in the Project Explorer view and files are loaded.

Compile

From IDE

After being done with the downloading and opening project, select Build Project option from Build menu.

Detailed Description

• Creating MorphologicalDisambiguator
• Training MorphologicalDisambiguator
• Sentence Disambiguation

Creating MorphologicalDisambiguator

MorphologicalDisambiguator provides Turkish morphological disambiguation. There are possible disambiguation techniques. Depending on the technique used, disambiguator can be instantiated as follows:

• Using RootFirstDisambiguation, the one that chooses only the root amongst the given analyses

    morphologicalDisambiguator = new RootFirstDisambiguation()
  

• Using RootWordStatisticsDisambiguation, the one that chooses the root that is the most frequently used amongst the given analyses

    morphologicalDisambiguator = new RootWordStatisticsDisambiguation()
  

• Using LongestRootFirstDisambiguation, the one that chooses the longest root among the given roots

    morphologicalDisambiguator = new LongestRootFirstDisambiguation()
  

• Using HmmDisambiguation, the one that chooses using an Hmm-based algorithm

    morphologicalDisambiguator = new HmmDisambiguation()
  

• Using DummyDisambiguation, the one that chooses a random one amongst the given analyses

    morphologicalDisambiguator = new DummyDisambiguation()
  

Training MorphologicalDisambiguator

To train the disambiguator, an instance of DisambiguationCorpus object is needed. This can be instantiated and the disambiguator can be trained and saved as follows:

DisambiguationCorpus corpus = new DisambiguationCorpus("penn_treebank.txt");
morphologicalDisambiguator.train(corpus);
morphologicalDisambiguator.saveModel();

Sentence Disambiguation

To disambiguate a sentence, a FsmMorphologicalAnalyzer instance is required. This can be created as below, further information can be found here.

FsmMorphologicalAnalyzer fsm = new FsmMorphologicalAnalyzer();

A sentence can be disambiguated as follows:

Sentence sentence = new Sentence("Yarın doktora gidecekler");
FsmParseList[] fsmParseList = fsm.robustMorphologicalAnalysis(sentence);
System.out.println("All parses");
System.out.println("--------------------------");
for(int i = 0; i < fsmParseList.length; i++){
    System.out.println(fsmParseList[i]);
}
ArrayList<FsmParse> candidateParses = morphologicalDisambiguator.disambiguate(fsmParseList);
System.out.println("Parses after disambiguation");
System.out.println("--------------------------");
for(int i = 0; i < candidateParses.size(); i++){
    System.out.println(candidateParses.get(i));
}

Output

All parses
--------------------------
yar+NOUN+A3SG+P2SG+NOM
yar+NOUN+A3SG+PNON+GEN
yar+VERB+POS+IMP+A2PL
yarı+NOUN+A3SG+P2SG+NOM
yarın+NOUN+A3SG+PNON+NOM

doktor+NOUN+A3SG+PNON+DAT
doktora+NOUN+A3SG+PNON+NOM

git+VERB+POS+FUT+A3PL
git+VERB+POS^DB+NOUN+FUTPART+A3PL+PNON+NOM

Parses after disambiguation
--------------------------
yarın+NOUN+A3SG+PNON+NOM
doktor+NOUN+A3SG+PNON+DAT
git+VERB+POS+FUT+A3PL

Cite

@InProceedings{gorgunyildiz12,
author="G{\"o}rg{\"u}n, Onur
and Yildiz, Olcay Taner",
editor="Gelenbe, Erol
and Lent, Ricardo
and Sakellari, Georgia",
title="A Novel Approach to Morphological Disambiguation for Turkish",
booktitle="Computer and Information Sciences II",
year="2012",
publisher="Springer London",
address="London",
pages="77--83",
isbn="978-1-4471-2155-8"
}

For Contibutors

Conan Setup

1. First install conan.

pip install conan

Instructions are given in the following page:

https://docs.conan.io/2/installation.html

2. Add conan remote 'ozyegin' with IP: 104.247.163.162 with the following command:

conan remote add ozyegin http://104.247.163.162:8081/artifactory/api/conan/conan-local --insert

3. Use the comman conan list to check for installed packages. Probably there are no installed packages.

conan list

conanfile.py file

1. Put the correct dependencies in the requires part

    requires = ["math/1.0.0", "classification/1.0.0"]

2. Default settings are:

    settings = "os", "compiler", "build_type", "arch"
    options = {"shared": [True, False], "fPIC": [True, False]}
    default_options = {"shared": True, "fPIC": True}
    exports_sources = "src/*", "Test/*"

    def layout(self):
        cmake_layout(self, src_folder="src")

    def generate(self):
        tc = CMakeToolchain(self)
        tc.generate()
        deps = CMakeDeps(self)
        deps.generate()

    def build(self):
        cmake = CMake(self)
        cmake.configure()
        cmake.build()

    def package(self):
        copy(conanfile=self, keep_path=False, src=join(self.source_folder), dst=join(self.package_folder, "include"), pattern="*.h")
        copy(conanfile=self, keep_path=False, src=self.build_folder, dst=join(self.package_folder, "lib"), pattern="*.a")
        copy(conanfile=self, keep_path=False, src=self.build_folder, dst=join(self.package_folder, "lib"), pattern="*.so")
        copy(conanfile=self, keep_path=False, src=self.build_folder, dst=join(self.package_folder, "lib"), pattern="*.dylib")
        copy(conanfile=self, keep_path=False, src=self.build_folder, dst=join(self.package_folder, "bin"), pattern="*.dll")

    def package_info(self):
        self.cpp_info.libs = ["ComputationalGraph"]

CMakeLists.txt file

1. Set the C++ standard with compiler flags.

	set(CMAKE_CXX_STANDARD 20)
	set(CMAKE_CXX_FLAGS "-O3")

2. Dependent packages should be given with find_package.

	find_package(util_c REQUIRED)
	find_package(data_structure_c REQUIRED)

3. For library part, use add_library and target_link_libraries commands. Use m library for math linker in Linux.

	add_library(Math src/Distribution.cpp src/Distribution.h src/DiscreteDistribution.cpp src/DiscreteDistribution.h src/Vector.cpp src/Vector.h src/Eigenvector.cpp src/Eigenvector.h src/Matrix.cpp src/Matrix.h src/Tensor.cpp src/Tensor.h)
	target_link_libraries(Math util_c::util_c data_structure_c::data_structure_c m)

4. For executable tests, use add_executable and target_link_libraries commands. Use m library for math linker in Linux.

	add_executable(DiscreteDistributionTest src/Distribution.cpp src/Distribution.h src/DiscreteDistribution.cpp src/DiscreteDistribution.h src/Vector.cpp src/Vector.h src/Eigenvector.cpp src/Eigenvector.h src/Matrix.cpp src/Matrix.h src/Tensor.cpp src/Tensor.h Test/DiscreteDistributionTest.cpp)
	target_link_libraries(DiscreteDistributionTest util_c::util_c data_structure_c::data_structure_c m)

Data files

1. Add data files to the cmake-build-debug folder.

C++ files

1. If needed, comparator operators == and < should be implemented for map and set data structures.

    bool operator==(const Word &anotherWord) const{
        return (name == anotherWord.name);
    }
    bool operator<(const Word &anotherWord) const{
        return (name < anotherWord.name);
    }

2. Do not forget to comment each function.

	/**
 	* A constructor of Word class which gets a String name as an input and assigns to the name variable.
	*
	* @param _name String input.
 	*/
	Word::Word(const string &_name) {

3. Function names should follow caml case.

	int Word::charCount() const

4. Write getter and setter methods.

	string Word::getName() const
	void Word::setName(const string &_name)

5. Use catch.hpp for testing purposes. Add

#define CATCH_CONFIG_MAIN  // This tells Catch to provide a main() - only do this in one cpp file

line in only one of the test files. Add

#include "catch.hpp"

line in all test files. Example test file is given below:

TEST_CASE("DictionaryTest") {
    TxtDictionary lowerCaseDictionary = TxtDictionary("lowercase.txt", "turkish_misspellings.txt");
    TxtDictionary mixedCaseDictionary = TxtDictionary("mixedcase.txt", "turkish_misspellings.txt");
    TxtDictionary dictionary = TxtDictionary();
    SECTION("testSize"){
        REQUIRE(29 == lowerCaseDictionary.size());
        REQUIRE(58 == mixedCaseDictionary.size());
        REQUIRE(62113 == dictionary.size());
    }
    SECTION("testGetWord"){
        for (int i = 0; i < dictionary.size(); i++){
            REQUIRE_FALSE(nullptr == dictionary.getWord(i));
        }
    }
    SECTION("testLongestWordSize"){
        REQUIRE(1 == lowerCaseDictionary.longestWordSize());
        REQUIRE(1 == mixedCaseDictionary.longestWordSize());
        REQUIRE(21 == dictionary.longestWordSize());
    }

6. Enumerated types should be declared with enum class.

	enum class Pos {
		ADJECTIVE,
		NOUN,
		VERB,
		ADVERB,

7. Every header file should start with

	#ifndef MATH_DISTRIBUTION_H
	#define MATH_DISTRIBUTION_H

and end with

	#endif //MATH_DISTRIBUTION_H

8. Do not forget to use const expression for parameters, if they will not be changed in the function.

	void Word::setName(const string &_name);

9. Do not forget to use const expression for methods, which do not modify any class attribute. Also use [[dodiscard]]

	[[nodiscard]] bool isPunctuation() const;

10. Use xmlparser package for parsing xml files.

    auto* doc = new XmlDocument("test.xml");
    doc->parse();
    XmlElement* root = doc->getFirstChild();
    XmlElement* firstChild = root->getFirstChild();

11. Data structures: Use map for hash map, unordered_map for linked hash map, vector for array list, unordered_set for hash set