Session 6

Author

Masaki EGUCHI, Ph.D.

Modified

August 4, 2025

One-liner

You will learn how to derive major lexical diversity and sophistication indices.

🎯 Learning Objectives

By the end of this session, you will be able to:

  • Compute simple lexical diversity measures using spreadsheet software
  • Compute advanced lexical diversity measures using TAALED
  • Explain how modern lexical diversity measures are calculated
  • Calculate simple lexical sophistication measures using dedicated web application
  • Describe how lexical sophistication measures behave on a single input text.
  • Discuss benefits and drawbacks of lexical richness measures.

🔑 Key Concepts

  • lexical diversity
  • lexical sophistication
  • Learner corpus research

🛠️ Tools Used

📚 Required Readings

  • (Skim) Durrant Ch. 4 (Ignore R codes if you are not familiar)

🌊 Dive Deeper - Recommended Readings

  • Bestgen, Y. (2025). Estimating lexical diversity using the moving average type-token ratio (MATTR): Pros and cons. Research Methods in Applied Linguistics, 4(1), 100168. https://doi.org/10.1016/j.rmal.2024.100168
  • Kyle, K., Crossley, S., & Berger, C. (2018). The tool for the automatic analysis of lexical sophistication (TAALES): Version 2.0. Behavior Research Methods, 50(3), 1030–1046. https://doi.org/10.3758/s13428-017-0924-4
  • Kyle, K., Crossley, S. A., & Jarvis, S. (2021). Assessing the Validity of Lexical Diversity Indices Using Direct Judgements. Language Assessment Quarterly, 18(2), 154–170. https://doi.org/10.1080/15434303.2020.1844205
  • Kyle, K., Sung, H., Eguchi, M., & Zenker, F. (2024). Evaluating evidence for the reliability and validity of lexical diversity indices in L2 oral task responses. Studies in Second Language Acquisition, 46(1), 278–299. https://doi.org/10.1017/S0272263123000402

Materials

Slides for the session

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Reflection