Adams, R., & Nik, N. M. (2014). Prior knowledge and second language task production in text chat.
System, 42, 1-12.
https://doi.org/10.1016/j.system.2013.10.011
Ahmadian, M. J., & Tavakoli, M. (2021). The effects of simultaneous use of careful online planning and task repetition on accuracy, complexity, and fluency in EFL learners’ oral production.
Language Teaching Research, 25(3), 382-404.
https://doi.org/10.1177/1362168819858249
Awwad, A. A., & Tavakoli, P. (2019).
Task complexity, language proficiency and working memory: Interaction effects on second language speech performance.
International Review of Applied Linguistics in Language Teaching (IRAL), 60(2), 169-196. DOI: 10.1515/iral.2018.0378
Behtary, S., & Yaghoubi-Notash, M. (2009). Explorations in L2 Speech Variability: A case for length constraint as task demand. Rassegna Italiana di Linguistica Applicata, 41(3), 191-206.
De Jong, N., & Perfetti, C. A. (2021). Fluency training in the ESL classroom: An experimental study of fluency development and proceduralization.
Language Learning, 61(2), 533-568.
https://doi.org/10.1111/j.1467-9922.2010.00620.x
Divsar, H. (2020). The comparative effect of rehearsal, strategic, and online planning on the fluency, accuracy, complexity, lexical variety, and attentional allocation of EFL learners’ argumentative writing. Teaching English as a Second Language Quarterly (TESLQ), 41(2), 75-111. DOI: 10.22099/TESL.2021.41004.3017
Divsar, H. (2022). The impact of planning time types on complexity, accuracy, fluency, and lexical diversity in EFL learners’ writing.
Language Teaching Research, 26(1), 3-24.
https://doi.org/10.1177/1362168820906287
Ellis, R. (2018). Reflections on task-based language teaching. Multilingual Matters.
Ellis, R. (2024). Rod Ellis’s essential bookshelf: Focus on form. Language Teaching, 57, 246–261 doi:10.1017/S026144482200012X
Ellis, R., Skehan, P., Li, S., Shintani, N., & Lambert, C. (Eds.). (2020). Task-based language teaching: Theory and practice. Cambridge University Press. DOI: 10.1017/9781108643689
Foster, P., & Skehan, P. (1996). The influence of planning and task type on second language performance. Studies in Second language acquisition, 18(3), 299-323.
Foster, P., & Skehan, P. (1999). The influence of source of planning and focus of planning on task-based performance. Language teaching research, 3(3), 215-247.
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.
García-Ponce, E. E., Mora-Pablo, I., & Segovia-Hernández, J. G. (2022). Role of EFL learners’ perceptions of task difficulty in complexity, accuracy and fluency: An exploratory case study.
Porta Linguarum, 37, 123-142. DOI:
https://doi.org/10.30827/portalin.vi37.15855
Hsu, H. (2023). Lexical diversity in constrained vs. unconstrained L2 narrative tasks.
TESOL Quarterly, 57(1), 78-102.
https://doi.org/10.1002/tesq.312
Jackson, D. O., & Suethanapornkul, S. (2023). Time pressure and L2 oral performance: A trade-off between complexity and accuracy.
Language Learning, 73(1), 45-72.
https://doi.org/10.1111/lang.12512
Jin, T., Lu, X., & Ni, J. (2020). Attentional allocation in L2 task-based performance: A cognitive load perspective.
Applied Linguistics, 41(5), 712-735.
https://doi.org/10.1093/applin/amz046
Kormos, J., & Trebits, A. (2022). Task modality and pair formation method in L2 oral interaction.
Language Teaching Research, 26(4), 567-589.
https://doi.org/10.1177/1362168820906288
Kuiken, F., Mos, M., & Vedder, I. (2005). Cognitive Task Complexity and Second Language Writing Performance. EUROSLA Yearbook, 5, 195-222. DOI: 10.1075/eurosla.5.10kui
Kuiken, F., & Vedder, I. (2007). Task complexity and measures of linguistic performance in L2 writing. International Review of Applied Linguistics in Language Teaching (IRAL), 45(3), 261-284. DOI: 10.1515/iral.2007.012
Kuiken, F., & Vedder, I. (2012). Syntactic complexity, lexical variation and accuracy as a function of task complexity and proficiency level in L2 writing and speaking. In A. Housen, F. Kuiken, & I. Vedder (Eds.)
Dimensions of L2 performance and proficiency: Complexity, accuracy and fluency in SLA (pp. 143-170). John Benjamins.
https://doi.org/10.1075/lllt.32.07kui
Lambert, C., & Kormos, J. (2024). Dynamic systems and task complexity: A longitudinal study of L2 performance.
Studies in Second Language Acquisition, 46(1), 1-25.
https://doi.org/10.1017/S027226312300045X
Luo, S. (2022). Task complexity and L2 performance: A meta-analysis.
Language Learning, 72(1), 152-183.
https://doi.org/10.1111/lang.12472
Malvern, D., & Richards, B. (2002). Investigating accommodation in language proficiency interviews using a new measure of lexical diversity. Language testing, 19(1), 85-104.
Mehnert, U. (1998). The effects of different lengths of time for planning on second language performance. Studies in second language acquisition, 20(1), 83-108.
Michel, M. C., Kuiken, F., & Vedder, I. (2007). The influence of complexity in monologic versus dialogic tasks in Dutch L2.
International Review of Applied Linguistics in Language Teaching (IRAL),
45(3), 241-259. DOI:
10.1515/iral.2007.011
Michel, M., & Kormos, J. (2023). Working memory and task conditions in L2 speech production.
Applied Psycholinguistics, 44(2), 301-328.
https://doi.org/10.1017/S0142716422000425
Readable.com (2025). What is readability? Retrieved July 30, 2025, from https://readable.com/readability/what-is-readability/
Robinson, P. (2001). Task complexity, task difficulty, and task production: Exploring interactions in a componential framework (p. 3). Applied linguistics, 22(1), 27-57.
Robinson, P. (2007). Task complexity, theory of mind, and intentional reasoning: Effects on L2 speech production, interaction, uptake and perceptions of task difficulty International Review of Applied Linguistics in Language Teaching (IRAL), 45(3), 193-213. DOI: 10.1515/iral.2007.009
Robinson, P. (Ed.). (2011). Second language task complexity: Researching the cognition hypothesis of language learning and performance (Vol. 2). John Benjamins Publishing.
Saito, K., & Hanzawa, K. (2022). Working memory and L2 oral fluency under time pressure.
Language Learning, 72(3), 789-820.
https://doi.org/10.1111/lang.12498
Sasayama, S. (2016). Is a ‘Complex’ Task Really Complex? Validating the Assumption of Cognitive Task Complexity.
The Modern Language Journal, 100(1), 231-254.
https://doi.org/10.1111/modl.12313
Sasayama, S., & Malicka, A. (2022). The role of task complexity in L2 performance: A meta-analysis.
TESOL Quarterly, 56(2), 341-369.
https://doi.org/10.1002/tesq.307
Skehan, P. (2009). Modelling second language performance: Integrating complexity, accuracy, fluency, and lexis. Applied linguistics, 30(4), 510-532.
Skehan, P. (2014). Task-based performance and task-based instruction: Research contributions.
Skehan, P., & Foster, P. (1999). The influence of task structure and processing conditions on narrative retellings (p. 4). Language learning, 49(1), 93-120.
Suzuki, Y., & Sunada, M. (2023). Fluency development through task repetition: The role of working memory.
Studies in Second Language Acquisition, 45(1), 1-25.
https://doi.org/10.1017/S0272263122000362
Swain, M. (1985). Communicative competence: Some roles of comprehensible input and comprehensible output in its development. Input in second language acquisition, 15, 165-179.
Tavakoli, P., & Foster, P. (2021). Task design and second language performance: The effect of narrative type on learner output.
Language Learning, 71(1), 75-104.
https://doi.org/10.1111/lang.12425
Tavakoli, P., & Hunter, A. M. (2018). Is fluency being ‘neglected ‘in the classroom? Teacher understanding of fluency and related classroom practices. Language Teaching Research, 22(3), 330-349.
Tavakoli, P., Nakatsuhara, F., & Hunter, A. M. (2017). Validating speaking test rating scales through microanalysis of fluency using PRAAT.
Tavakoli, P., & Skehan, P. (2005). Strategic planning, task structure and performance testing. In Planning and task performance in a second language (pp. 239-273). John Benjamins.
Van den Branden, K. (Ed.). (2006a). Task-based language education: From theory to practice. Cambridge University Press. https://doi.org/10.1017/cbo9780511667282
Van den Branden, K. (2006b). Introduction: Task-based language teaching in a nutshell. In K. Van den Branden (Ed.), Task-based language education: From theory to practice (pp. 1-16). Cambridge University Press. https://doi.org/10.1017/cbo9780511667282
Vasylets, O.,
Gilabert, R., &
Manchón, M. M. (2017). The Effects of mode and task complexity on second language production. Language Learning, 67(2), 394-430. https://doi.org/10.1111/lang.12228
Wang, Z. (2013). The effects of task complexity on L2 lexical complexity.
Modern Language Journal, 97(1), 82-97.
https://doi.org/10.1111/j.1540-4781.2013.01431.x
Wiggleworth, G. (2001). Influences on performance in task-based oral assessments. In M. Bygate, P. Skehan, & M. Swain (Eds.),
Researching pedagogic tasks: Second language learning, teaching, and testing (pp. 186-209). Longman. Xing, M. (2019). Task complexity and second language production: A meta-analysis.
System, 84, 1-12.
https://doi.org/10.1016/j.system.2019.05.003
Zohrabi, M., & Hasanpour, S. (2020). The effect of open vs. closed tasks on Improving Iranian EFL learners’ oral performance.
Teaching English as a Second Language Quarterly (TSOLQ),
38(4), 205-238.
https://doi.org/10.22099/jtls.2020.37075.2814