{"history":[],"article":{"id":"068d2577-ed54-4068-8e73-41af70df56f5","title":"Morphological dictionary","slug":"morphological-dictionary","content":":::summary\n:::\n\n# \nIn the fields of [computational linguistics](https://bliptext.com/articles/computational-linguistics) and [applied linguistics](https://bliptext.com/articles/applied-linguistics), a **morphological dictionary** is a linguistic resource that contains correspondences between surface form and lexical forms of words.\nSurface forms of words are those found in natural language text.\nThe corresponding lexical form of a surface form is the [lemma](https://bliptext.com/articles/lemma-morphology) followed by grammatical information (for example the [part of speech](https://bliptext.com/articles/part-of-speech), [gender](https://bliptext.com/articles/grammatical-gender) and [number](https://bliptext.com/articles/grammatical-number)).\nIn English give, gives, giving, gave and given are surface forms of the verb give.\nThe lexical form would be \"give\", verb.\nThere are two kinds of morphological dictionaries: morpheme-aligned dictionaries and full-form (non-aligned) dictionaries.\n\n# Notable examples and formalisms\n\n## Universal Morphologies\nInspired by the success of the [Universal Dependencies](https://bliptext.com/articles/universal-dependencies) for cross-linguistic annotation of syntactic dependencies, similar efforts have emerged for morphology, e.g., UniMorph and UDer.\nThese feature simple tabular ([tab-separated](https://bliptext.com/articles/tab-separated-values)) formats with one form in a row, and its derivation (UDer), resp., inflection information (UniMorph): aalen aalend V.PTCP;PRS\naalen aalen V;IND;PRS;1;PL\naalen aalen V;IND;PRS;3;PL\naalen aalen V;NFIN\n(UniMorph, German. Columns are LEMMA, FORM, FEATURES) In UDer, additional information (part of speech) is encoded within the columns: abändern_V Abänderung_Nf dVN07>\nAbarbeiten_Nn abarbeiten_V dNV09>\nabartig_A Abartigkeit_Nf dAN03>\nAbart_Nf abartig_A dNA05>\nabbaggern_V Abbaggern_Nn dVN09>\n(UDer, German DErivBase 0.5. Columns are BASE, DERIVED, RULE) At the time of writing (2021), all of these are non-aligned morphological dictionaries (see below).\nTheir simplistic format is particularly well-suited for the application of machine learning techniques, and UniMorph in particular, has been subject of numerous shared tasks.\n\n## Finite State Transducers\n[Finite State Transducers](https://bliptext.com/articles/finite-state-transducer) (FSTs) are a popular technique for the computational handling of morphology, esp., inflectional morphology.\nIn rule-based morphological parsers, both lexicon and rules are normally formalized as finite state automata and subsequently combined.\nThey thus require morphological dictionaries with specific processing instructions (which often have a linguistic interpretation, but, technically, are just treated like arbitrary string symbols).\nPopular FST packages such as SFST (as available from the fst package in Debian and Ubuntu) allow to define application-specific file formats for morphological lexica, that bundle different pieces of morphological information with every individual morpheme.\nThese are thus aligned morphological dictionaries, but very rich (and also, idiosyncratic) in structure.\nSample data from SMOR (German SFST grammar): Aachen

\nAal \nAarau

\n nom<>:e<>:n\n nom \n nom\n\n## Interlinear Glossed Text editors\n[Interlinear Glossed Text (IGT)](https://bliptext.com/articles/interlinear-gloss) is a popular formalism in language documentation, linguistic typology and other branches of linguistics and the philologies.\nAlthough IGT can be created without any specialized software (but just with a conventional editor), such specialized software has been developed, with notable examples such as Toolbox, the FieldWorks Language Explorer (FLEx) or open source alternatives such as Xigt.\nToolbox and FLEx support semi-automated annotation by means of an internal morphological dictionary.\nWhenever a morphological segment is encountered for which an annotation in the dictionary can be found, this annotations is applied.\nWhenever a morphological segment is newly annotated, the annotation is stored in the dictionary.\nFLEx and Toolbox provide different editor functionalities for annotating text and editing dictionaries, so that additional information beyond that found in annotations can be added, but at its core, their formats provide aligned morphological dictionaries.\nFLEx and Xigt are based on XML formats, Toolbox uses a plain text format with idiosyncratic \"markers\".\nFLEx and Toolbox are not directly interoperable with each other, but a semiautomated converter for Toolbox to FLEx does exist.\nXigt comes with FLEx and Toolbox importers, but is less widely used that either FLEx or Toolbox.\nTheir formats of FLEx and Toolbox are not intended for human consumption, nor are they well-supported by any processing software other than their native tools.\n\n## OntoLex-Morph: A community standard for morphological dictionaries\n[OntoLex](https://bliptext.com/articles/ontolex) is a community standard for machine-readable dictionaries on the web.\nIn 2019, the OntoLex-Morph module has been proposed to facilitate data modelling of morphology in lexicography, as well as to provide a data model for morphological dictionaries for Natural Language Processing.\nOntoLex-Morph does support both aligned and non-aligned morphological dictionaries.\nA specific goal is to establish interoperability between and among IGT dictionaries, FST lexicons and morphological dictionaries used for machine learning.\n\n# Types and structure of morphological dictionaries\n\n## Aligned morphological dictionaries\nIn an aligned morphological dictionary, the correspondence between the surface form and the lexical form of a word is aligned at the character level, for example:\nWhere θ is the empty symbol and ⟨n⟩ signifies \"noun\", and ⟨pl⟩ signifies \"plural\".\nIn the example the left hand side is the surface form (input), and the right hand side is the lexical form (output).\nThis order is used in [morphological analysis](https://bliptext.com/articles/morphology-linguistics) where a lexical form is generated from a surface form.\nIn morphological generation this order would be reversed.\nFormally, if Σ is the alphabet of the input symbols, and \\Gamma is the alphabet of the output symbols, an aligned morphological dictionary is a subset, where:\nis the alphabet of all the possible alignments including the empty symbol.\nThat is, an aligned morphological dictionary is a set of string in L^*.\n\n## Non-aligned morphological dictionaries (full-form dictionaries)\nA non-aligned morphological dictionary (or full-form dictionary) is simply a set of pairs of input and output strings.\nA non-aligned morphological dictionary would represent the previous example as:\nIt is possible to convert a non-aligned dictionary into an aligned dictionary.\nBesides trivial alignments to the left or to the right, linguistically motivated alignments which align characters to their corresponding morphemes are possible.\n\n## Lexical ambiguities\nFrequently there exists more than one lexical form associated with a surface form of a word.\nFor example, \"house\" may be a noun in the singular,, or may be a verb in the present tense,.\nAs a result of this it is necessary to have a function which relates input strings with their corresponding output strings.\nIf we define the set of input words such that, the correspondence function would be defined as.","current_revision":null,"created_by":"kACnuQmH5k9Nr5VNVEpVeg7XpvUmMctD","created_at":"2025-01-26T10:20:44.189Z","updated_at":"2025-01-26T10:20:44.189Z","search_vector":"'dictionari':2 'morpholog':1","search_content":" \n \n\n# \nIn the fields of [computational linguistics](https://bliptext.com/articles/computational-linguistics) and [applied linguistics](https://bliptext.com/articles/applied-linguistics), a **morphological dictionary** is a linguistic resource that contains correspondences between surface form and lexical forms of words.\nSurface forms of words are those found in natural language text.\nThe corresponding lexical form of a surface form is the [lemma](https://bliptext.com/articles/lemma-morphology) followed by grammatical information (for example the [part of speech](https://bliptext.com/articles/part-of-speech), [gender](https://bliptext.com/articles/grammatical-gender) and [number](https://bliptext.com/articles/grammatical-number)).\nIn English give, gives, giving, gave and given are surface forms of the verb give.\nThe lexical form would be \"give\", verb.\nThere are two kinds of morphological dictionaries: morpheme-aligned dictionaries and full-form (non-aligned) dictionaries.\n\n# Notable examples and formalisms\n\n## Universal Morphologies\nInspired by the success of the [Universal Dependencies](https://bliptext.com/articles/universal-dependencies) for cross-linguistic annotation of syntactic dependencies, similar efforts have emerged for morphology, e.g., UniMorph and UDer.\nThese feature simple tabular ([tab-separated](https://bliptext.com/articles/tab-separated-values)) formats with one form in a row, and its derivation (UDer), resp., inflection information (UniMorph): aalen aalend V.PTCP;PRS\naalen aalen V;IND;PRS;1;PL\naalen aalen V;IND;PRS;3;PL\naalen aalen V;NFIN\n(UniMorph, German. Columns are LEMMA, FORM, FEATURES) In UDer, additional information (part of speech) is encoded within the columns: abändern_V Abänderung_Nf dVN07>\nAbarbeiten_Nn abarbeiten_V dNV09>\nabartig_A Abartigkeit_Nf dAN03>\nAbart_Nf abartig_A dNA05>\nabbaggern_V Abbaggern_Nn dVN09>\n(UDer, German DErivBase 0.5. Columns are BASE, DERIVED, RULE) At the time of writing (2021), all of these are non-aligned morphological dictionaries (see below).\nTheir simplistic format is particularly well-suited for the application of machine learning techniques, and UniMorph in particular, has been subject of numerous shared tasks.\n\n## Finite State Transducers\n[Finite State Transducers](https://bliptext.com/articles/finite-state-transducer) (FSTs) are a popular technique for the computational handling of morphology, esp., inflectional morphology.\nIn rule-based morphological parsers, both lexicon and rules are normally formalized as finite state automata and subsequently combined.\nThey thus require morphological dictionaries with specific processing instructions (which often have a linguistic interpretation, but, technically, are just treated like arbitrary string symbols).\nPopular FST packages such as SFST (as available from the fst package in Debian and Ubuntu) allow to define application-specific file formats for morphological lexica, that bundle different pieces of morphological information with every individual morpheme.\nThese are thus aligned morphological dictionaries, but very rich (and also, idiosyncratic) in structure.\nSample data from SMOR (German SFST grammar): Aachen \n Aal \n Aarau \n nom<>:e<>:n \n nom \n nom \n\n## Interlinear Glossed Text editors\n[Interlinear Glossed Text (IGT)](https://bliptext.com/articles/interlinear-gloss) is a popular formalism in language documentation, linguistic typology and other branches of linguistics and the philologies.\nAlthough IGT can be created without any specialized software (but just with a conventional editor), such specialized software has been developed, with notable examples such as Toolbox, the FieldWorks Language Explorer (FLEx) or open source alternatives such as Xigt.\nToolbox and FLEx support semi-automated annotation by means of an internal morphological dictionary.\nWhenever a morphological segment is encountered for which an annotation in the dictionary can be found, this annotations is applied.\nWhenever a morphological segment is newly annotated, the annotation is stored in the dictionary.\nFLEx and Toolbox provide different editor functionalities for annotating text and editing dictionaries, so that additional information beyond that found in annotations can be added, but at its core, their formats provide aligned morphological dictionaries.\nFLEx and Xigt are based on XML formats, Toolbox uses a plain text format with idiosyncratic \"markers\".\nFLEx and Toolbox are not directly interoperable with each other, but a semiautomated converter for Toolbox to FLEx does exist.\nXigt comes with FLEx and Toolbox importers, but is less widely used that either FLEx or Toolbox.\nTheir formats of FLEx and Toolbox are not intended for human consumption, nor are they well-supported by any processing software other than their native tools.\n\n## OntoLex-Morph: A community standard for morphological dictionaries\n[OntoLex](https://bliptext.com/articles/ontolex) is a community standard for machine-readable dictionaries on the web.\nIn 2019, the OntoLex-Morph module has been proposed to facilitate data modelling of morphology in lexicography, as well as to provide a data model for morphological dictionaries for Natural Language Processing.\nOntoLex-Morph does support both aligned and non-aligned morphological dictionaries.\nA specific goal is to establish interoperability between and among IGT dictionaries, FST lexicons and morphological dictionaries used for machine learning.\n\n# Types and structure of morphological dictionaries\n\n## Aligned morphological dictionaries\nIn an aligned morphological dictionary, the correspondence between the surface form and the lexical form of a word is aligned at the character level, for example:\nWhere θ is the empty symbol and ⟨n⟩ signifies \"noun\", and ⟨pl⟩ signifies \"plural\".\nIn the example the left hand side is the surface form (input), and the right hand side is the lexical form (output).\nThis order is used in [morphological analysis](https://bliptext.com/articles/morphology-linguistics) where a lexical form is generated from a surface form.\nIn morphological generation this order would be reversed.\nFormally, if Σ is the alphabet of the input symbols, and \\Gamma is the alphabet of the output symbols, an aligned morphological dictionary is a subset, where:\nis the alphabet of all the possible alignments including the empty symbol.\nThat is, an aligned morphological dictionary is a set of string in L^*.\n\n## Non-aligned morphological dictionaries (full-form dictionaries)\nA non-aligned morphological dictionary (or full-form dictionary) is simply a set of pairs of input and output strings.\nA non-aligned morphological dictionary would represent the previous example as:\nIt is possible to convert a non-aligned dictionary into an aligned dictionary.\nBesides trivial alignments to the left or to the right, linguistically motivated alignments which align characters to their corresponding morphemes are possible.\n\n## Lexical ambiguities\nFrequently there exists more than one lexical form associated with a surface form of a word.\nFor example, \"house\" may be a noun in the singular,, or may be a verb in the present tense,.\nAs a result of this it is necessary to have a function which relates input strings with their corresponding output strings.\nIf we define the set of input words such that, the correspondence function would be defined as.","revisionCount":0},"hasMore":false,"nextCursor":null}

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