Class 9

Lexicography and Lexicon Theory

In this class, lexicography and lexicon theory will be discussed.

• What is the structure of a lexicon?
• How can lexicons be described?
• How can lexicons be made?

This will be illustrated by examples from English.

Lexicon Theory

Lexicon theory is the branch that deals with theories of lexicon development and structures of lexica. We can distinguish three different structures:

• Microstructure: denotes the smallest surface structure of a lexicon. Surface structure here means the structure that can be seen without the analysis of individual entries or - referring to relational databases - the setup of the tables before inserting anything else.

  The design of the microstructure depends on the purpose of the lexicon and the intended user group.

  In principal the structure consists of three levels

  1. concept level: linking to the macrostructure;
  2. first level: all different words (synonyms, etc.), definitions, related concepts, examples, technical information, domain;
  3. second level(language dependent): constituents of the first level's components, such as grammatical information, pronunciation, etymology, morphology of the (individual terms), etc.
• Macrostructure: the structure according to which categorisation and search functions can be defined. In general it is possible to differentiate between two different models:

  1. Semasiological macrostructure: A semasiological macrostructure is formbased, assigning meaning to a form. Taking a word A as an example: To understand the concept denoted by word A one takes the surface structure (e.g. the orthographic representation, phonetic transcription, morphological structure) and looks for the definition and usage of the word.

     The most common way of organising dictionaries and encyclopaedia is the use of the orthographic representation - the spelling - to search for further explanation. The result may be a single definition or in cases of homographs more than one definition, enabling the user to decide which one to take, most of the time with the help of more surface information such as collocation, part of speech, context, etc. Some dictionaries contain even more information about the term, such as pronunciation, register of usage, regional variations, etymology and so on. Related terms are rarely listed, no hierarchic classification is achieved

  2. Onomasiological macrostructure: The onomasiological macrostructure is not form based but concept/meaning oriented. Not a form of representation is the key to a term but its semantic field and related concepts. Consequently, the definition does not play the most important part but the classification and position in a taxonomy. Searching for the above mentioned word A the user of an onomasiological dictionary does not need any surface form, such as the orthography, but the basic understanding of the concept. Looking for the term screwdriver for example a user could search in a dictionary for metal processing, then for tools, continuing with tools for moving material and usage with screws, ending up with screwdriver. In this case screwdriver also inherits information from the other terms, i.e.: the term has all properties of the superordinate concepts.

• Generalisations: the list of rules with which more -- inflected and derived -- forms can be composed. Sometimes this structure is calle meso-structure analoguous to micro and macro-structures.

• Metadata: Metainformation on the lexicon, such as the lexicographer(s), applied theories, language, date, qualification, characterset, formalisms, etc.

Exercise: Have a look at the dictionary entries and try to describe the microstructure of theses entries. It might help you to write one entry in a tabel format and find a table heading.

Exercise: Which generalisations can you find on the pages for verbs! Describe the rules.

Lexicography

Questionnaire based Lexicography

Traditionally linguist starting research in one language start with a questionnaire. This questionnaire is specifically designed according to their needs, especially in respects of:

• intended use: researching morphology, use in computer systems, translation
• intended usergroup: experts, lay, translators, linguists,
• intended coverage: general, special purpose
• available sources: availability of language experts (native speakers)

The following questionnaire for example was designed for a comparative study of Australian languages by studying motion-verbs in different (Aboridginal) languages.

Sample Questionnaire

In class exercise: Create a questionnaire that will provide all information to schedule a business appointment if filled in.

Lexicon Theory

Lexicon theory is the branch that deals with theories of lexicon development and structures of lexica. We can distinguish three different structures:

• Microstructure: denotes the smallest surface structure of a lexicon. Surface structure here means the structure that can be seen without the analysis of individual entries or - referring to relational databases - the setup of the tables before inserting anything else.

  The design of the microstructure depends on the purpose of the lexicon and the intended user group.

  In principal the structure consists of three levels

  1. concept level: linking to the macrostructure;
  2. first level: all different words (synonyms, etc.), definitions, related concepts, examples, technical information, domain;
  3. second level(language dependent): constituents of the first level's components, such as grammatical information, pronunciation, etymology, morphology of the (individual terms), etc.
• Macrostructure: the structure according to which categorisation and search functions can be defined. In general it is possible to differentiate between two different models:

  1. Semasiological macrostructure: A semasiological macrostructure is formbased, assigning meaning to a form. Taking a word A as an example: To understand the concept denoted by word A one takes the surface structure (e.g. the orthographic representation, phonetic transcription, morphological structure) and looks for the definition and usage of the word.

     The most common way of organising dictionaries and encyclopaedia is the use of the orthographic representation - the spelling - to search for further explanation. The result may be a single definition or in cases of homographs more than one definition, enabling the user to decide which one to take, most of the time with the help of more surface information such as collocation, part of speech, context, etc. Some dictionaries contain even more information about the term, such as pronunciation, register of usage, regional variations, etymology and so on. Related terms are rarely listed, no hierarchic classification is achieved

  2. Onomasiological macrostructure: The onomasiological macrostructure is not form based but concept/meaning oriented. Not a form of representation is the key to a term but its semantic field and related concepts. Consequently, the definition does not play the most important part but the classification and position in a taxonomy. Searching for the above mentioned word A the user of an onomasiological dictionary does not need any surface form, such as the orthography, but the basic understanding of the concept. Looking for the term screwdriver for example a user could search in a dictionary for metal processing, then for tools, continuing with tools for moving material and usage with screws, ending up with screwdriver. In this case screwdriver also inherits information from the other terms, i.e.: the term has all properties of the superordinate concepts.
• Generalisations: the list of rules with which more -- inflected and derived -- forms can be composed. Sometimes this structure is calle meso-structure analoguous to micro and macro-structures.
• Metadata: Metainformation on the lexicon, such as the lexicographer(s), applied theories, language, date, qualification, characterset, formalisms, etc.

Exercise: Have a look at the dictionary entries and try to describe the microstructure of theses entries. It might help you to write one entry in a tabel format and find a table heading.

Exercise: Which generalisations can you find on the pages for verbs! Describe the rules.

Lexicography

Questionnaire based Lexicography

Traditionally linguist starting research in one language start with a questionnaire. This questionnaire is specifically designed according to their needs, especially in respects of:

• intended use: researching morphology, use in computer systems, translation
• intended usergroup: experts, lay, translators, linguists,
• intended coverage: general, special purpose
• available sources: availability of language experts (native speakers)

The following questionnaire for example was designed for a comparative study of Australian languages by studying motion-verbs in different (Aboridginal) languages.

Sample Questionnaire

In class exercise: Create a questionnaire that will provide all information to schedule a business appointment if filled in.

Reading assignment for June 26: Van Eynde, Frank and Dafydd GibbonLexicon Development for Speech and Language Processing, chapter "Computational Lexicography", section 3.5 (p. 22-27)

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