Analyzing lexical features to predict Indian ITAs’ performance in a university oral English assessment

This study investigates the extent to which lexical features can predict human rater assessments of high-performing Indian International Teaching Assistants (ITAs), examining whether metrics of lexical diversity, sophistication, and collocational use predict between Level 4 and Level 5 ratings. To address this question, sixty-six speaking test transcripts from Indian ITAs were analyzed using computational tools that generate quantitative measures of vocabulary use, including TAALES and TAALED. Binary logistic regression analysis revealed that while lexical diversity measures did not significantly predict between advanced proficiency levels, lexical sophistication measures (word frequency) and collocational metrics demonstrated moderate predictive power. The findings show a complex pattern where Level 5 candidates tend to use less frequent individual words but more conventional multi-word expressions, suggesting sophisticated vocabulary deployment that balances precision with accessibility. These results contribute to both the theoretical understanding of lexical development at advanced proficiency levels and the practical assessment of ITAs, suggesting that beyond a certain threshold, lexical sophistication and collocational competence play more decisive roles than diversity in predicting highly proficient speakers.

Name thesis:degree_name

M.A.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Teaching of English Sec Lang

Grantor

University of Illinois Urbana-Champaign

Year dc:date

2025

Author dc:creator

• Rahman, Raihan

Contributors dc:contributor

• Yan, Xun
• Zhang, Qiusi

• Oral English assessment
• Lexical features
• lexical diversity
• lexical sophistication
• collocational use
• Indian ITAs
• language proficiency
• TESL

Statement dc:rights

• Copyright 2025 Raihan Rahman

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/129522

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F129522