Predictive structure or paradigm size? Investigating the effects of i-complexity and e-complexity on the learnability of morphological systems

Research on cross-linguistic differences in morphological paradigms reveals a wide range of variation on many dimensions, including the number of categories expressed, the number of unique forms, and the number of inflectional classes. However, in an influential paper, Ackerman & Malouf (2013) a...

Full description

Bibliographic Details
Main Authors: Tamar Johnson, Kexin Gao, Kenny Smith, Hugh Rabagliati, Jennifer Culbertson
Format: Article
Language:English
Published: Institute of Computer Science, Polish Academy of Sciences 2021-10-01
Series:Journal of Language Modelling
Subjects:
Online Access:https://jlm.ipipan.waw.pl/index.php/JLM/article/view/259
_version_ 1818286162477842432
author Tamar Johnson
Kexin Gao
Kenny Smith
Hugh Rabagliati
Jennifer Culbertson
author_facet Tamar Johnson
Kexin Gao
Kenny Smith
Hugh Rabagliati
Jennifer Culbertson
author_sort Tamar Johnson
collection DOAJ
description Research on cross-linguistic differences in morphological paradigms reveals a wide range of variation on many dimensions, including the number of categories expressed, the number of unique forms, and the number of inflectional classes. However, in an influential paper, Ackerman & Malouf (2013) argue that there is one dimension on which languages do not differ widely: in predictive structure. Predictive structure in a paradigm describes the extent to which forms predict each other, called i-complexity. Ackerman & Malouf (2013) show that although languages differ according to measure of surface paradigm complexity, called e-complexity, they tend to have low i-complexity. They conclude that morphological paradigms have evolved under a pressure for low i-complexity, such that even paradigms with very high e-complexity are relatively easy to learn so long as they have low i-complexity. While this would potentially explain why languages are able to maintain large paradigms, recent work by Johnson et al. (submitted) suggests that both neural networks and human learners may actually be more sensitive to e-complexity than i-complexity. Here we will build on this work, reporting a series of experiments under more realistic learning conditions which confirm that indeed, across a range of paradigms that vary in either e- or i-complexity, neural networks (LSTMs) are sensitive to both, but show a larger effect of e-complexity (and other measures associated with size and diversity of forms). In human learners, we fail to find any effect of i-complexity at all. Further, analysis of a large number of randomly generated paradigms show that e- and i-complexity are negatively correlated: paradigms with high e-complexity necessarily show low i-complexity.These findings suggest that the observations made by Ackerman & Malouf (2013) for natural language paradigms may stem from the nature of these measures rather than learning pressures specially attuned to i-complexity.
first_indexed 2024-12-13T01:20:13Z
format Article
id doaj.art-e2ffbc5013da4c0dbcd97901704ea408
institution Directory Open Access Journal
issn 2299-856X
2299-8470
language English
last_indexed 2024-12-13T01:20:13Z
publishDate 2021-10-01
publisher Institute of Computer Science, Polish Academy of Sciences
record_format Article
series Journal of Language Modelling
spelling doaj.art-e2ffbc5013da4c0dbcd97901704ea4082022-12-22T00:04:15ZengInstitute of Computer Science, Polish Academy of SciencesJournal of Language Modelling2299-856X2299-84702021-10-019110.15398/jlm.v9i1.259Predictive structure or paradigm size? Investigating the effects of i-complexity and e-complexity on the learnability of morphological systemsTamar Johnson0Kexin GaoKenny SmithHugh RabagliatiJennifer CulbertsonUniversity of EdinburghResearch on cross-linguistic differences in morphological paradigms reveals a wide range of variation on many dimensions, including the number of categories expressed, the number of unique forms, and the number of inflectional classes. However, in an influential paper, Ackerman & Malouf (2013) argue that there is one dimension on which languages do not differ widely: in predictive structure. Predictive structure in a paradigm describes the extent to which forms predict each other, called i-complexity. Ackerman & Malouf (2013) show that although languages differ according to measure of surface paradigm complexity, called e-complexity, they tend to have low i-complexity. They conclude that morphological paradigms have evolved under a pressure for low i-complexity, such that even paradigms with very high e-complexity are relatively easy to learn so long as they have low i-complexity. While this would potentially explain why languages are able to maintain large paradigms, recent work by Johnson et al. (submitted) suggests that both neural networks and human learners may actually be more sensitive to e-complexity than i-complexity. Here we will build on this work, reporting a series of experiments under more realistic learning conditions which confirm that indeed, across a range of paradigms that vary in either e- or i-complexity, neural networks (LSTMs) are sensitive to both, but show a larger effect of e-complexity (and other measures associated with size and diversity of forms). In human learners, we fail to find any effect of i-complexity at all. Further, analysis of a large number of randomly generated paradigms show that e- and i-complexity are negatively correlated: paradigms with high e-complexity necessarily show low i-complexity.These findings suggest that the observations made by Ackerman & Malouf (2013) for natural language paradigms may stem from the nature of these measures rather than learning pressures specially attuned to i-complexity.https://jlm.ipipan.waw.pl/index.php/JLM/article/view/259morphological complexitylearningneural networkstypology
spellingShingle Tamar Johnson
Kexin Gao
Kenny Smith
Hugh Rabagliati
Jennifer Culbertson
Predictive structure or paradigm size? Investigating the effects of i-complexity and e-complexity on the learnability of morphological systems
Journal of Language Modelling
morphological complexity
learning
neural networks
typology
title Predictive structure or paradigm size? Investigating the effects of i-complexity and e-complexity on the learnability of morphological systems
title_full Predictive structure or paradigm size? Investigating the effects of i-complexity and e-complexity on the learnability of morphological systems
title_fullStr Predictive structure or paradigm size? Investigating the effects of i-complexity and e-complexity on the learnability of morphological systems
title_full_unstemmed Predictive structure or paradigm size? Investigating the effects of i-complexity and e-complexity on the learnability of morphological systems
title_short Predictive structure or paradigm size? Investigating the effects of i-complexity and e-complexity on the learnability of morphological systems
title_sort predictive structure or paradigm size investigating the effects of i complexity and e complexity on the learnability of morphological systems
topic morphological complexity
learning
neural networks
typology
url https://jlm.ipipan.waw.pl/index.php/JLM/article/view/259
work_keys_str_mv AT tamarjohnson predictivestructureorparadigmsizeinvestigatingtheeffectsoficomplexityandecomplexityonthelearnabilityofmorphologicalsystems
AT kexingao predictivestructureorparadigmsizeinvestigatingtheeffectsoficomplexityandecomplexityonthelearnabilityofmorphologicalsystems
AT kennysmith predictivestructureorparadigmsizeinvestigatingtheeffectsoficomplexityandecomplexityonthelearnabilityofmorphologicalsystems
AT hughrabagliati predictivestructureorparadigmsizeinvestigatingtheeffectsoficomplexityandecomplexityonthelearnabilityofmorphologicalsystems
AT jenniferculbertson predictivestructureorparadigmsizeinvestigatingtheeffectsoficomplexityandecomplexityonthelearnabilityofmorphologicalsystems