An Investigation of Complexity, Accuracy, and Fluency in the Speech of EFL Learners

Zdeňka Neumanová

doi:10.31261/TAPSLA.15946

Published: 2025-06-23

Vol. 11 No. 1 (2025)

An Investigation of Complexity, Accuracy, and Fluency in the Speech of EFL Learners

Zdeňka Neumanová

Section: Articles

https://doi.org/10.31261/TAPSLA.15946

Abstract

This study investigates the relationship between several quantitative measures of L2 speech complexity, accuracy, and fluency (CAF) by comparing the oral productions of English L2 learners at different proficiency levels. Forty English as a Foreign Language (EFL) learners of varied proficiency levels performed a simple oral task. The performance of the L2 learners was analyzed regarding linguistic complexity, accuracy, and fluency to investigate the interplay of the CAF dimensions and how language proficiency levels (A2, B1, and B2) relate to these dimensions in the speech of EFL learners. This study confirms the prevailing view that the three CAF dimensions are interconnected and that the CAF triad is a useful and valid way to investigate and describe L2 performance development. The results indicate that all three dimensions of CAF significantly predict L2 learnersʼ oral proficiency, that is, from the developmental perspective, L2 learnersʼ output is produced with higher complexity, accuracy, and fluency as they progress to a higher proficiency level. Moreover, the current paper discusses ways to measure CAF. Specific measures of complexity (index of developmental levels), accuracy (syntactic error rate), and fluency (articulation rate, and dysfluency rate) were identified as effective discriminators between proficiency levels.

Keywords:

accuracy , complexity , fluency , L2 , proficiency

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Neumanová, Z. (2025). An Investigation of Complexity, Accuracy, and Fluency in the Speech of EFL Learners. Theory and Practice of Second Language Acquisition, 11(1), 1–22. https://doi.org/10.31261/TAPSLA.15946

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References

Anderson, C. (2007). The CEFR and the need for more research. Modern Language Journal, 91(4), 659–663.
Google Scholar

Baddeley, A. (2007). Working memory, thought, and action. Oxford University Press.
Google Scholar

Barrot, J., & Gabinete, M. K. (2021). Complexity, accuracy, and fluency in the argumentative writing of ESL and EFL learners. International Review of Applied Linguistics in Language Teaching, 59(2), 209–232.
Google Scholar

Biber, D., Johansson, S., Leech, G., Conrad, S., & Finegan, E. (1999). Longman grammar of spoken and written English. Pearson.
Google Scholar

Biber, D., & Conrad, S. (2001). Quantitative corpus-based research: Much more than bean counting. TESOL Quarterly, 35(2), 331–336.
Google Scholar

Biber, D., Gray, B., & Poonpon, K. (2011). Should we use characteristics of conversation to measure grammatical complexity in L2 writing development? TESOL Quarterly, 45(1), 5–35.
Google Scholar

Bosker, H. R., Pinget, A.-F., Quené, H., Sanders, T., & de Jong, N. H. (2013). What makes speech sound fluent? The contributions of pauses, speed and repairs. Language Testing, 30, 159–175.
Google Scholar

Bulté, B., & Housen, A. (2012). Defining and operationalising L2 complexity. In A. Housen, F. Kuiken, & I. Vedder (Eds.), Dimensions of L2 performance and proficiency: Complexity, accuracy and fluency in SLA (pp. 23–46). John Benjamins.
Google Scholar

De Felice, R., & Pulman, S. (2009). Automatic detection of preposition errors in learner writing. CALICO Journal, 26(3), 512–528.
Google Scholar

DeKeyser, R. (2007). Skill acquisition theory. In B. Van Patten & J. Williams (Eds.), Theories in Second Language Acquisition: An Introduction (pp. 94–112). Lawrence Erlbaum.
Google Scholar

Ellis, R. (1994). The study of second language acquisition. Oxford University Press.
Google Scholar

Ellis, R. (1997). Second Language Acquisition. Oxford University Press.
Google Scholar

Ellis, R. (2003). Task-based language learning and teaching. Oxford University Press.
Google Scholar

Ellis, R. (2008). The Study of Second Language Acquisition (2nd edition). Oxford University Press.
Google Scholar

Ellis, R., & Barkhuizen, G. (2005). Analyzing learner language. Oxford University Press.
Google Scholar

Ferrari, S. (2012). A longitudinal study of complexity, accuracy, and fluency variation in second language development. In A. Housen, F. Kuiken, & I. Vedder (Eds.), Dimensions of L2 performance and proficiency: Complexity, accuracy, and fluency in SLA (pp. 277–298). John Benjamins Publishing Company.
Google Scholar

Fleiss, J. L., Levin, B., & Paik, M. C. (2013). Statistical methods for rates and proportions. John Wiley & Sons.
Google Scholar

Foster, P., & Wigglesworth, G. (2016). Capturing accuracy in second language performance: The case for a weighted clause ratio. Annual Review of Applied Linguistics, 36, 98–116.
Google Scholar

Gilquin, G., & De Cock, S. (2011). Errors and disfluencies in spoken corpora: Setting the Scene. International Journal of Corpus Linguistics, 16(2), 141–172.
Google Scholar

Gráf, T. (2015). Accuracy and fluency in the speech of the advanced learner of English. Univerzita Karlova v Praze.
Google Scholar

Granger, S., Swallow, H., & Thewissen, J. (2022). The Louvain Error Tagging Manual. Version 2.0. CECL Papers 4. Centre for English Corpus Linguistics: Louvain-la-Neuve.
Google Scholar

Gunnarsson, C. (2012). The development of complexity, accuracy, and fluency in the written production of L2 French. In A. Housen, F. Kuiken, & I. Vedder (Eds.), Dimensions of L2 Performance and Proficiency: Complexity, Accuracy, and Fluency in SLA (pp. 247–276). John Benjamins Publishing Company.
Google Scholar

Gyllstad, H., Granfeldt, J., Bernardini, P., & Källkvist, M. (2014). Linguistic correlates to communicative proficiency levels of the CEFR. The case of syntactic complexity in written L2 English, L3 French and L4 Italian. EUROSLA Yearbook, 14, 1–30.
Google Scholar

Harrison, J., & Barker, F. (2015). English profile studies: English profile in practice. Cambridge University Press.
Google Scholar

Hokamura, M. (2018). The dynamics of complexity, accuracy, and fluency: A longitudinal case study of Japanese learners’ English writing. JALT Journal, 40(1), 23–46.
Google Scholar

Housen, A., & Kuiken, F. (2009). Complexity, accuracy, and fluency in Second Language Acquisition. Applied Linguistics, 30(4), 461–473.
Google Scholar

Housen, A., Kuiken, F., & Vedder, I. (2012). Dimensions of L2 performance and proficiency: Complexity, accuracy, and fluency in SLA. John Benjamins Publishing Company.
Google Scholar

Huang, L.-F., & Gráf, T. (2020). Speech rate and pausing in English: Comparing learners at different levels of proficiency with native speakers. Taiwan Journal of TESOL, 17(1), 57–86.
Google Scholar

Hulstijn, J. H. (2011). Language proficiency in native and nonnative speakers: An agenda for research and suggestions for second-language assessment. Language Assessment Quarterly, 8(3), 229–249.
Google Scholar

Iwashita, N., Brown, A., McNamara, T., & O’Hagan, S. (2008). Assessed levels of second language speaking proficiency: How distinct? Applied Linguistics, 29(1), 24–49.
Google Scholar

Jones, N., & Saville, N. (2009). European language policy: Assessment, learning, and the CEFR. Annual Review of Applied Linguistics, 29, 51–63.
Google Scholar

Kormos, J., & Dénes, M. (2004). Exploring measures and perceptions of fluency in the speech of second language learners. System, 32(2), 145–164.
Google Scholar

Kowal, I. (2018). The dynamics of complexity, accuracy, and fluency in second language development. Jagiellonian University Press.
Google Scholar

Kuiken, F., & Vedder, I. (2014). Rating written performance: What do raters do and why? Language Testing, 31(3), 329–348.
Google Scholar

Lambert, C., & Kormos, J. (2014). Complexity, accuracy, and fluency in task based L2 research: Toward more developmentally based measures of second language acquisition. Applied Linguistics, 35(5), 607–614.
Google Scholar

Larsen-Freeman, D. (2006). The emergence of complexity, fluency, and accuracy in the oral and written production of the Chinese learners of English. Applied Linguistics, 27(4), 590–619.
Google Scholar

Larsen-Freeman, D. (2009). Adjusting expectations: The study of complexity, accuracy, and fluency in second language acquisition. Applied Linguistics, 30(4), 579–589.
Google Scholar

Lennon, P. (1990). Investigating fluency in EFL: A quantitative approach. Language Learning, 40(3), 387–417.
Google Scholar

Lennon, P. (2000). The lexical element in spoken second language fluency. In H. Riggenbach (Ed.), Perspectives on fluency (pp. 25–42). University of Michigan Press.
Google Scholar

Michel, M. C. (2017). Complexity, accuracy, and fluency in L2 production. In S. Loewen & M. Sato (Eds.), The Routledge handbook of instructed second language acquisition (pp. 50–68). Taylor & Francis.
Google Scholar

Miyamoto, M. (2019). Capturing L2 oral proficiency with CAF measures as predictors of the ACTFL OPI rating. [Doctoral dissertation, Purdue University, School of Languages and Cultures, West Lafayette, Indiana, 2019].
Google Scholar

Mora, J. C. (2006). Age Effect on Oral Fluency Development. In C. Muñoz (Ed.), Age and the Rate of Foreign Language Learning (pp. 65–88). Multilingual Matters.
Google Scholar

Mostafa, T., Kim, Y., & Friginal, E. (2020). Examining a developmentally based measure of L2 oral performances: Does it predict L2 learners’ oral proficiency? System, 89, 1–16.
Google Scholar

Nation, I. S. P. (2009a). Teaching ESL/EFL reading and writing. Routledge.
Google Scholar

Nation, I. S. P. (2009b). Teaching ESL/EFL listening and speaking. Routledge.
Google Scholar

Nation, I. S. P. (2011). Research into practice: Vocabulary. Language Teaching, 44(4), 1–11.
Google Scholar

Norris, J. M., & Ortega, L. (2009). Towards an organic approach to investigating CAF in instructed SLA: The case of complexity. Applied Linguistics, 30(4), 555–578.
Google Scholar

Ortega, L. (2003). Syntactic complexity measures and their relationship to L2 proficiency: A research synthesis of college-level L2 writing. Applied Linguistics, 24(4), 492–518.
Google Scholar

Ortega, L. (2014). Trying out theories on interlanguage: Description and explanation over 40 years of L2 negation research. In Z. Han & E. Tarone (Eds.), Interlanguage: Forty years later (pp. 173–202). John Benjamins.
Google Scholar

Palloti, G. (2009). CAF: Defining, refining, and differentiating constructs. Applied Linguistics, 30(4), 590–601.
Google Scholar

Pang F., & Skehan, P. (2014). What do learners do when they plan? In P. Skehan (Ed.), Processing perspectives on task performance (pp. 95–128). John Benjamins.
Google Scholar

Polat, B., & Kim, Y. (2013). Dynamics of complexity and accuracy: A longitudinal case study of advanced untutored development. Applied Linguistics, (35)2, 184–207.
Google Scholar

Polio, C. (1997). Measures of linguistic accuracy in second language writing research. Language Learning, 47, 101–143.
Google Scholar

Polio, C., & Shea, M. C. (2014). An investigation into current measures of linguistic accuracy in second language writing research. Journal of Second Language Writing, 26, 10–27.
Google Scholar

Porcino, M. C., & Finardi, K. R. (2012). The tension between accuracy and fluency of L2 speech: Evidence from communicative tasks. The ESPecialist, 33(1), 25–44.
Google Scholar

Robinson, P. (2003). The cognition hypothesis, task design, and adult task-based language learning. Second Language Studies, 21(2), 45–107.
Google Scholar

Robinson, P. (2005). Aptitude and second language acquisition. Annual Review of Applied Linguistics, 25, 46–73.
Google Scholar

Robinson, P. (2009). Syllabus design. In M. H. Long & C. J. Doughty (Eds.), The Handbook of Language Teaching (pp. 294–310). Blackwell Publishing.
Google Scholar

Robinson, P. (2011). Second language task complexity, the cognition hypothesis, language learning, and performance. In P. Robinson (Ed.), Second language task complexity: Researching the cognition hypothesis of language learning and performance (pp. 3–38). John Benjamins.
Google Scholar

Rossiter, M. J., Derwing, T. M., Manimtim, L. G., & Thomson, R. I. (2010). Oral fluency: The neglected component in the communicative language classroom. The Canadian Modern Language Review, 66(4), 583–606.
Google Scholar

Segalowitz, N. (2010). Cognitive bases of second language fluency. Routledge.
Google Scholar

Scrivener, J. (2005). Learning teaching: A guidebook for English language teachers. MacMillan Education.
Google Scholar

Shungo, S., & Kormos, J. (2020). Linguistic dimensions of comprehensibility and perceived fluency: An investigation of complexity, accuracy, and fluency in second language argumentative speech. Studies in Second Language Acquisition, 42(1), 143–167.
Google Scholar

Skehan, P. (2009). Modelling second language performance: Integrating complexity, accuracy, fluency, and lexis. Applied Linguistics, 30(4), 510–532.
Google Scholar

Skehan, P. (1998). A cognitive approach to language learning. Oxford University Press.
Google Scholar

Spoelman, M., & Verspoor, M. (2010). Dynamic patterns in the development of accuracy and complexity: A longitudinal case study in the acquisition of Finnish. Applied Linguistics, 31(4), 532–553.
Google Scholar

Tavakoli, P., & Skehan, P. (2005). Strategic planning, task structure, and performance testing. In R. Ellis (Ed.), Planning and task performance in a second language (pp. 239–273). Benjamins.
Google Scholar

Taylor, D. (1988). The meaning and use of the term ‘competenceʼ in linguistics and applied linguistics. Applied Linguistics, 9, 148–168.
Google Scholar

Van Ek, J. A., & Trim, J. L. M. (1991a). Waystage 1990. Council of Europe/Cambridge University Press.
Google Scholar

Van Ek, J. A., & Trim, J. L. M. (1991b). Threshold 1990. Council of Europe/Cambridge University Press.
Google Scholar

Van Ek, J. A., & Trim, J. L. M. (2001). Vantage. Council of Europe/Cambridge University Press.
Google Scholar

Wolfe-Quintero, K., Inagaki, S., & Kim, H.-Y. (1998). Second language development in writing: Measures of fluency, accuracy, and complexity. University of Hawaii, Second Language Teaching and Curriculum Center.
Google Scholar

Wood, D. (2012). Formulaic language and second language speech fluency: Background, evidence and classroom applications. Continuum.
Google Scholar

Zhang, M. (2018). Collaborative writing in the EFL classroom: The effects of L1 and L2 use. System, 76, 1–12.
Google Scholar