Base Form

From UNL Wiki
(Difference between revisions)
Jump to: navigation, search
m (Examples)
 
(50 intermediate revisions by 3 users not shown)
Line 1: Line 1:
In the UNLarium framework, '''base form''' is the form used to generate all variants (inflections) of a given [[LRU]].  
+
'''Base Form''', or simply BF, is the form used to generate all variants of a given [[morphology|lexeme]].  
  
== LRUs and BFs ==
+
The [[lemma]] is not always the most adequate form used to generate the inflections of a given lexeme. Consider, for instance, the case of “take into account”, which is actually a discontinuous item, since we can have any noun phrase between “take” and “into account”: “take <u>that</u> into account”, “take <u>it</u> into account”, “take <u>the decision of proliferating dictionary fields</u> into account”, etc. In order to be prepared to process all those possibilities, we have to create a different lexical entity: the '''base form'''. In the case of “take into account”, the base form will be “take”. From the base form, we will be able not only to associate the lexeme to an existing inflectional paradigm (“take”) but also to treat discontinuity and order issues through simple and deterministic generation rules.
 
+
A single concept may have several different realisations in a given language. These variations are of two types:
+
*Internal variations, i.e., related to the same lexical realisation unit, such as in “to die”, “die”, “dies”, “dying”, “died”, etc, which are represented by the same lemma “die” as a single LRU; and
+
*External variations, such as “die”, “decease”, “pass away”, “perish”, etc, which are represented by different lemmas and different LRUs in the UNLarium.
+
 
+
As the LRU is the basic unit of the UNLarium, each external variation will correspond to a different entry, but internal variations will be represented inside the same entry and will be generated automatically through inflectional and/or subcategorization rules.  In many cases, however, the LRU, which is actually a lemma, is not the most adequate form to guide the process of generating the internal variations. In such cases, we will need a “base form”, i.e., a lexical realisation that is more suitable for automatic processing.
+
 
+
Consider, for instance, the case of the LRU “take into account”, which is actually a discontinuous item, since we can have any noun phrase between “take” and “into account”: “take that into account”, “take it into account”, “take the decision of proliferating dictionary fields into account”, etc. In order to be prepared to process all those possibilities, we have to create a different lexical entity, which will be exactly the '''base form'''. In the case of “take into account”, the base form will be “take”. From the base form, we will be able not only to associate the LRU to an existing inflectional paradigm (“take”) but also to treat discontinuity and order issues through simple and deterministic generation rules.
+
  
 
== How to create a BF ==
 
== How to create a BF ==
There are four main rules for creating BFs.
+
The BF is the same as the lemma, except in case of multi-word expressions that involve discontinuity or infixation, i.e., where variations cannot be generated by simple prefixation and/or suffixation rules. In these cases, the BF will correspond to the lemma of the '''longest common denominator''' between all the possible variations of the LRU.
*A BF should be created only in case of '''compound or complex LRUs''', i.e., LRUs that contain more than one word, whether concatenated or separated by hyphen or spaces.
+
 
*A BF should be created if and only if it is '''indispensable''' to the generation of the internal variations of a given LRU, i.e., if the variations cannot be generated by simple prefixation and/or suffixation rules.
+
=== Examples ===
*A BF should '''preserve the lexical category''' of the corresponding LRU. If the LRU is a verb, so will be the BF.
+
*house (simple word): BF=lemma="house"<br>
*A BF should correspond to the '''longest common denominator''' between all the possible variations of the corresponding LRU.
+
*mouse (simple word with infixation: "mouse">"mice"): BF=lemma="mouse"<br>
 +
*coffee house (multi-word expression without infixation: "coffee house">"coffee houses"): BF=lemma="coffee house"<br>
 +
*give in (multi-word expression with infixation: "give in">"gave in"): BF="give" <code>&ne;</code> lemma="give in"<br>
 +
*behind one's back (discontinuous multi-word expression without infixation: "behind my back", "behind his back", etc): BF="behind" <code>&ne;</code> lemma="behind <person>'s back"<br>
 +
*take into account (discontinuous multi-word LRU with infixation: "take it into account", "took that into account"): BF="take" <code>&ne;</code> lemma="take into account"
  
 
== The use of BF ==
 
== The use of BF ==
  
The use of BFs is derived from a practical limitation rather than from a logical necessity.  In order to be efficient and to avoid overcharging the system, generation rules have to be as general and few as possible, and that limits considerably the possibility of creating infixation rules. The alternative is to reduce infixable compounds and complex LRUs to the highest common denominator (i.e., to “hyper-regularise” them) in order to treat infixation as a special case of prefixation or suffixation.  
+
The use of BFs is derived from a practical limitation rather than from a logical necessity.  In order to be efficient and to avoid overcharging the system, generation rules have to be as general and few as possible, what limits considerably the possibility of creating infixation rules. The alternative is to reduce infixable compounds and multi-word expressions to the longest common denominator (i.e., to “hyper-regularise” them) in order to treat infixation as a special case of prefixation or suffixation.  
  
In English, the use of BF is limited to separable phrasal verbs (such as “bring (sth) back” or “look (sth) up”).  The need of BFs is more noteworthy in highly-inflective languages where compounds and complex LRUs may be reordered or infixed. Consider, for instance, the case of the simple LRU “lingua” (= “language”), in Latin. As a case-inflectional language, Latin normally has 12 different forms for each noun:
+
In English, the use of BF is limited to phrasal verbs (such as "give in" and "bring <thing> back”), verbal phrases ("play with fire") and other discontinuous expressions (such as "behind <person>'s back").  The need of BFs is more noteworthy in highly-inflective languages where compounds and complex multi-words may be reordered or infixed. Consider, for instance, the case of “lingua” (= “language”), in Latin. As a case-inflectional language, Latin normally has 12 different forms for each noun:
 
{| border="1" align="center" cellpadding="5"
 
{| border="1" align="center" cellpadding="5"
 
!case
 
!case
Line 28: Line 24:
 
!plural
 
!plural
 
|-
 
|-
|width="60px"|nominative
+
|width="150px"|'''nominative'''
|width="60px"|lingua
+
|width="150px"|lingu'''a'''
|width="60px"|linguae
+
|width="150px"|lingu'''ae'''
 
|-
 
|-
|vocative
+
|'''vocative'''
|lingua
+
|lingu'''a'''
|linguae
+
|lingu'''ae'''
 
|-
 
|-
|accusative
+
|'''accusative'''
|linguam
+
|lingu'''am'''
|linguas
+
|lingu'''as'''
 
|-
 
|-
|genitive
+
|'''genitive'''
|linguae
+
|lingu'''ae'''
|linguarum
+
|lingu'''arum'''
 
|-
 
|-
|dative
+
|'''dative'''
|linguae
+
|lingu'''ae'''
|linguis
+
|lingu'''is'''
 
|-
 
|-
|ablative
+
|'''ablative'''
|lingua
+
|lingu'''a'''
|linguis
+
|lingu'''is'''
 
|}
 
|}
For single-word LRUs, as “lingua” the process of case-inflection is relatively simple, because it will be always correspond to a suffix. In complex LRUs, however, the process can be quite more complicated, because of the agreement. For “lingua franca”, for instance, we will have again 12 different forms, but generating them is no longer as simple as adding suffixes to the right of the LRU.
+
For single words, as “lingua”, the process of case-inflection is relatively simple, because it is extremely regular and will always correspond to a suffix. In multi-word expressions, however, the process can be quite more complicated, because of infixation and agreement. For “lingua franca”, for instance, we will have again 12 different forms, but generating them is no longer as simple as adding suffixes to the right of the string.
 
{| border="1" align="center" cellpadding="5"
 
{| border="1" align="center" cellpadding="5"
 
!case
 
!case
Line 58: Line 54:
 
!plural
 
!plural
 
|-
 
|-
|width="60px"|nominative
+
|width="150px"|'''nominative'''
|width="60px"|lingua franca
+
|width="150px"|lingu'''a''' franc'''a'''
|width="60px"|linguae francae
+
|width="150px"|lingu'''ae''' franc'''ae'''
 +
|-
 +
|'''vocative'''
 +
|lingu'''a''' franc'''a'''
 +
|lingu'''ae''' franc'''ae'''
 +
|-
 +
|'''accusative'''
 +
|lingu'''am''' franc'''am'''
 +
|lingu'''as''' franc'''as'''
 +
|-
 +
|'''genitive'''
 +
|lingu'''ae''' franc'''ae'''
 +
|lingu'''arum''' franc'''arum'''
 +
|-
 +
|'''dative'''
 +
|lingu'''ae''' franc'''ae'''
 +
|lingu'''is''' franc'''is'''
 +
|-
 +
|'''ablative'''
 +
|lingu'''a''' franc'''a'''
 +
|lingu'''is''' franc'''is'''
 +
|}
 +
In order to avoid listing all variations of “lingua franca” or creating a very specific rule which would apply only in this case, we reduce “lingua franca” to “lingua” and create a special rule for generating “franca” later on. The lemma will be then “lingua franca”, but the BF will be only “lingua”.
 +
 
 +
== Examples ==
 +
 
 +
{| border="1" align="center" cellpadding="5"
 +
!Word forms
 +
!Lemma
 +
!Base Form (BF)
 +
|-
 +
|apple, apples
 +
|apple
 +
|apple
 +
|-
 +
|city, cities
 +
|city
 +
|city
 +
|-
 +
|glasses
 +
|glasses
 +
|glasses
 +
|-
 +
|rosa, rosae, rosam, rosas, rosarum, rosis
 +
|rosa
 +
|rosa
 +
|-
 +
|beautiful
 +
|beautiful
 +
|beautiful
 +
|-
 +
|hermoso, hermosa, hermosos, hermosas
 +
|hermoso
 +
|hermoso
 +
|-
 +
|sum, es, est, sumus, estis, sunt, eram, fui…
 +
|esse
 +
|esse
 +
|-
 +
|part of speech, parts of speech
 +
|part of speech
 +
|part
 
|-
 
|-
|vocative
+
|skinhead, skinheads
|lingua franca
+
|skinhead
|linguae francae
+
|skinhead
 
|-
 
|-
|accusative
+
|give in, gives in, gave in, given in, …
|linguam francam
+
|give in
|linguas francas
+
|give
 
|-
 
|-
|genitive
+
|pars orationis, partes orationis, partem orationis, partis orationis, …
|linguae francae
+
|pars orationis
|linguarum francarum
+
|pars
 
|-
 
|-
|dative
+
|bring [sth] back, brings [sth] back, bringing [sth] back, brought [sth] back, ...
|linguae francae
+
|bring back
|linguis francis
+
|bring
 
|-
 
|-
|ablative
+
|play with fire, plays with fire, playing with fire, ...
|lingua franca
+
|play with fire
|linguis francis
+
|play
 
|}
 
|}
In order to avoid listing all variations of “lingua franca” inside the UNLarium or creating a very specific rule which would apply only in this case, we reduce “lingua franca” to “lingua” and create a special (subcategorization) rule for generating “franca” later on. The LRU will be then “lingua franca”, but the BF will be only “lingua”.
 

Latest revision as of 22:30, 11 March 2014

Base Form, or simply BF, is the form used to generate all variants of a given lexeme.

The lemma is not always the most adequate form used to generate the inflections of a given lexeme. Consider, for instance, the case of “take into account”, which is actually a discontinuous item, since we can have any noun phrase between “take” and “into account”: “take that into account”, “take it into account”, “take the decision of proliferating dictionary fields into account”, etc. In order to be prepared to process all those possibilities, we have to create a different lexical entity: the base form. In the case of “take into account”, the base form will be “take”. From the base form, we will be able not only to associate the lexeme to an existing inflectional paradigm (“take”) but also to treat discontinuity and order issues through simple and deterministic generation rules.

Contents

How to create a BF

The BF is the same as the lemma, except in case of multi-word expressions that involve discontinuity or infixation, i.e., where variations cannot be generated by simple prefixation and/or suffixation rules. In these cases, the BF will correspond to the lemma of the longest common denominator between all the possible variations of the LRU.

Examples

  • house (simple word): BF=lemma="house"
  • mouse (simple word with infixation: "mouse">"mice"): BF=lemma="mouse"
  • coffee house (multi-word expression without infixation: "coffee house">"coffee houses"): BF=lemma="coffee house"
  • give in (multi-word expression with infixation: "give in">"gave in"): BF="give" lemma="give in"
  • behind one's back (discontinuous multi-word expression without infixation: "behind my back", "behind his back", etc): BF="behind" lemma="behind <person>'s back"
  • take into account (discontinuous multi-word LRU with infixation: "take it into account", "took that into account"): BF="take" lemma="take into account"

The use of BF

The use of BFs is derived from a practical limitation rather than from a logical necessity. In order to be efficient and to avoid overcharging the system, generation rules have to be as general and few as possible, what limits considerably the possibility of creating infixation rules. The alternative is to reduce infixable compounds and multi-word expressions to the longest common denominator (i.e., to “hyper-regularise” them) in order to treat infixation as a special case of prefixation or suffixation.

In English, the use of BF is limited to phrasal verbs (such as "give in" and "bring <thing> back”), verbal phrases ("play with fire") and other discontinuous expressions (such as "behind <person>'s back"). The need of BFs is more noteworthy in highly-inflective languages where compounds and complex multi-words may be reordered or infixed. Consider, for instance, the case of “lingua” (= “language”), in Latin. As a case-inflectional language, Latin normally has 12 different forms for each noun:

case singular plural
nominative lingua linguae
vocative lingua linguae
accusative linguam linguas
genitive linguae linguarum
dative linguae linguis
ablative lingua linguis

For single words, as “lingua”, the process of case-inflection is relatively simple, because it is extremely regular and will always correspond to a suffix. In multi-word expressions, however, the process can be quite more complicated, because of infixation and agreement. For “lingua franca”, for instance, we will have again 12 different forms, but generating them is no longer as simple as adding suffixes to the right of the string.

case singular plural
nominative lingua franca linguae francae
vocative lingua franca linguae francae
accusative linguam francam linguas francas
genitive linguae francae linguarum francarum
dative linguae francae linguis francis
ablative lingua franca linguis francis

In order to avoid listing all variations of “lingua franca” or creating a very specific rule which would apply only in this case, we reduce “lingua franca” to “lingua” and create a special rule for generating “franca” later on. The lemma will be then “lingua franca”, but the BF will be only “lingua”.

Examples

Word forms Lemma Base Form (BF)
apple, apples apple apple
city, cities city city
glasses glasses glasses
rosa, rosae, rosam, rosas, rosarum, rosis rosa rosa
beautiful beautiful beautiful
hermoso, hermosa, hermosos, hermosas hermoso hermoso
sum, es, est, sumus, estis, sunt, eram, fui… esse esse
part of speech, parts of speech part of speech part
skinhead, skinheads skinhead skinhead
give in, gives in, gave in, given in, … give in give
pars orationis, partes orationis, partem orationis, partis orationis, … pars orationis pars
bring [sth] back, brings [sth] back, bringing [sth] back, brought [sth] back, ... bring back bring
play with fire, plays with fire, playing with fire, ... play with fire play
Software