The Challenge of Morphology

1
The Challenge of Morphology

• Mapudungun (Indigenous Language of Chile and
  Argentina, 1 Million Speakers)

Allkütulekefun
2
The Challenge of Morphology

• Mapudungun

-ke
-fu
-n
-le
Allkütu
3
The Challenge of Morphology

• Mapudungun

-ke
-fu
-n
-le
Allkütu
-past
-indic.1sg
-habitual
-prog.
Listen
4
The Challenge of Morphology

• Mapudungun

-ke
-fu
-n
-le
Allkütu
-past
-indic.1sg
-habitual
-prog.
Listen
I
5
The Challenge of Morphology

• Mapudungun

-ke
-fu
-n
-le
Allkütu
-past
-indic.1sg
-habitual
-prog.
Listen
I
used
to
6
The Challenge of Morphology

• Mapudungun

-ke
-fu
-n
-le
Allkütu
-past
-indic.1sg
-habitual
-prog.
Listen
I
used
to
listen
7
The Challenge of Morphology

• Mapudungun

• Tasks for Morphology
• Segment Words
• Map Morphemes onto Features

-ke
-fu
-n
-le
Allkütu
-past
-indic.1sg
-habitual
-prog.
Listen
I
used
to
listen
8
The Challenge of Morphology

• Tasks for Morphology
• Segment Words
• Map Morphemes onto Features

• Learn these tasks
• unsupervised
• from data
• for any language

9
Leverage the Natural Structure of Morphology

• Paradigm
• Set of affixes that interchangeably attach to a
  set of stems
• English Example
• Regular Verbs Ø.s.ing.ed
• Regular Adj Ø.er.est

10
Example Vocabulary blame blamed blames
roamed roaming roams solve
solves solving
11
Ø.s blame solve
Example Vocabulary blame blamed blames
roamed roaming roams solve
solves solving
12
Ø.s.d blame
Ø.s blame solve
Example Vocabulary blame blamed blames
roamed roaming roams solve
solves solving
13
Ø.s.d blame
Ø.s blame solve
Example Vocabulary blame blamed blames
roamed roaming roams solve
solves solving
14
Ø.s.d blame
Ø.s blame solve
Example Vocabulary blame blamed blames
roamed roaming roams solve
solves solving
s blame roam solve
15
Ø.s.d blame
Ø.s blame solve
Example Vocabulary blame blamed blames
roamed roaming roams solve
solves solving
s blame roam solve
16
Ø.s.d blame
Ø.s blame solve
e.es blam solv
Example Vocabulary blame blamed blames
roamed roaming roams solve
solves solving
s blame roam solve
17
Ø.s.d blame
Ø.s blame solve
e.es blam solv
Example Vocabulary blame blamed blames
roamed roaming roams solve
solves solving
s blame roam solve
18
Ø.s.d blame
e.es.ed blam
me.mes.med bla
e.es blam solv
Ø.s blame solve
me.mes bla
e.ed blam
Ø.d blame
me.med bla
s.d blame
es.ed blam
mes.med bla
Ø blame blames blamed roams roamed roaming solve s
olves solving
e blam solv
me bla
s blame roam solve
es blam solv
mes bla
ed blam roam
d blame roame
med bla roa
19
a.as.o.os.tro 1 cas

• Spanish Newswire Corpus
• 40,011 Tokens
• 6,975 Types

a.as.o.os 43 african, cas, jurídic, l, ...
a.as.os 50 afectad, cas, jurídic, l, ...
a.as.o 59 cas, citad, jurídic, l, ...
a.o.os 105 impuest, indonesi, italian, jurídic,
...
as.o.os 54 cas, implicad, jurídic, l, ...
a.as 199 huelg, incluid, industri, inundad, ...
a.os 134 impedid, impuest, indonesi, inundad, ...
as.os 68 cas, implicad, inundad, jurídic, ...
a.o 214 id, indi, indonesi, inmediat, ...
as.o 85 intern, jurídic, just, l, ...
a.tro 2 cas.cen
o.os 268 human, implicad, indici,
indocumentad, ...
a 1237 huelg, ib, id, iglesi, ...
as 404 huelg, huelguist, incluid, industri, ...
os 534 humorístic, human, hígad, impedid, ...
o 1139 hub, hug, human, huyend, ...
tro 16 catas, ce, cen, cua, ...
19
20
a.as.o.os.tro 1 cas
Suffixes Stems
Level 5 5 suffixes Stem Type Count
a.as.o.os 43 african, cas, jurídic, l, ...
a.as.os 50 afectad, cas, jurídic, l, ...
a.as.o 59 cas, citad, jurídic, l, ...
a.o.os 105 impuest, indonesi, italian, jurídic,
...
as.o.os 54 cas, implicad, jurídic, l, ...
a.as 199 huelg, incluid, industri, inundad, ...
a.os 134 impedid, impuest, indonesi, inundad, ...
as.os 68 cas, implicad, inundad, jurídic, ...
a.o 214 id, indi, indonesi, inmediat, ...
as.o 85 intern, jurídic, just, l, ...
a.tro 2 cas.cen
o.os 268 human, implicad, indici,
indocumentad, ...
a 1237 huelg, ib, id, iglesi, ...
as 404 huelg, huelguist, incluid, industri, ...
os 534 humorístic, human, hígad, impedid, ...
o 1139 hub, hug, human, huyend, ...
tro 16 catas, ce, cen, cua, ...
20
21
Adjective Inflection Class
From the spurious suffix tro
a.as.o.os 43 african, cas, jurídic, l, ...
a.as.os 50 afectad, cas, jurídic, l, ...
a.as.o 59 cas, citad, jurídic, l, ...
a.o.os 105 impuest, indonesi, italian, jurídic,
...
as.o.os 54 cas, implicad, jurídic, l, ...
a.as 199 huelg, incluid, industri, inundad, ...
a.os 134 impedid, impuest, indonesi, inundad, ...
as.os 68 cas, implicad, inundad, jurídic, ...
a.o 214 id, indi, indonesi, inmediat, ...
as.o 85 intern, jurídic, just, l, ...
o.os 268 human, implicad, indici,
indocumentad, ...
a 1237 huelg, ib, id, iglesi, ...
as 404 huelg, huelguist, incluid, industri, ...
os 534 humorístic, human, hígad, impedid, ...
o 1139 hub, hug, human, huyend, ...
21
22
Basic Search Procedure
a.as.o.os 43 african, cas, jurídic, l, ...
a.as.os 50 afectad, cas, jurídic, l, ...
a.as.o 59 cas, citad, jurídic, l, ...
a.o.os 105 impuest, indonesi, italian, jurídic,
...
as.o.os 54 cas, implicad, jurídic, l, ...
a.as 199 huelg, incluid, industri, inundad, ...
a.os 134 impedid, impuest, indonesi, inundad, ...
as.os 68 cas, implicad, inundad, jurídic, ...
a.o 214 id, indi, indonesi, inmediat, ...
as.o 85 intern, jurídic, just, l, ...
o.os 268 human, implicad, indici,
indocumentad, ...
a 1237 huelg, ib, id, iglesi, ...
as 404 huelg, huelguist, incluid, industri, ...
os 534 humorístic, human, hígad, impedid, ...
o 1139 hub, hug, human, huyend, ...
22
23
Scaling Up

• Scaling Up
• 1 Million word corpus
• Network built on demand
• New Approach to Search
• High Recall initial search
• Weed the results to improve precision
• Results
• Boost Recall of Suffixes in Spanish
• from 0.5 to 0.8
• But very low precision currently

24
Top Examples of Selected Schemes 1 Million Words
of Spanish
Suffixes of Stems Part of Speech
Ø.s 2 Noun
a.as.o.os 4 Adjective
Ø.ba.ban.da.das.do.dos.n.ndo.r.ron.rse.rá.rán.ría.rían 16 Verb (-ar)
Ø.es 2 Noun
a.aba.aban.ada.adas.ado.ados.an.ando.ar.ara.aron. arse.ará.arán.e.en.ó 18 Verb (-ar)
Ø.a.emos.on.se.á.án.ía.ían 9 Verb (-ar/-er/-ir)
ones.ón 2 Nominalization
l.les 2 Noun
25
Next Steps for Morphology Induction

• Clean the Selected Schemes
• Current Work
• Convert Paradigms into a Segmenter
• Soon
• Agglutinative sequences of suffixes
• Soon
• Learn Mappings from Morphemes to Features
• Future Goal