The Relationship Between Three Components of CAF in Learners’ Oral Performance at Different Proficiency Levels

Document Type : Research Paper


1 Department of English, Science and Research Branch, Islamic Azad University, Tehran, Iran

2 Department of English, Imam Ali University, Tehran, Iran


The current study aimed at finding out the relationship between complexity, accuracy, and fluency (CAF) in speaking performance across language proficiency levels with the focus on Skehan’s Trade-off Hypothesis. The selected participants of the present study included 60 language learners who were selected out of 90 learners. Through the results obtained from Oxford Placement Test, 21 participants were placed at elementary, 20 at intermediate, and 19 at advanced levels. The nationality of all participants was Iranian and therefore they shared similar L1 background. The sample participants were asked to perform the designed speaking tasks in different task complexities (low, mid, and high) and their oral CAF were measured and analyzed. To measure CAF, the percentage of error free C-units for accuracy, clauses per C-units for grammatical complexity, type-token ratio (TTR) for lexical complexity, and total number of tokens (words)/ total task time (per minutes) for fluency were used. The results of Pearson product-moment correlation revealed a significant positive relationship among complexity, accuracy, and fluency in oral performance. The results of the study indicate that there is variation in the process of gradual complexification in spoken L2 production across proficiency levels. In fact, the results of this study revealed distinguishing features in all three CAF components. Moreover, the findings of the present study provide pedagogical implications and recommendations for teachers, syllabus designers, and language assessors. Finally, some suggestions for other interested researchers in this field are presented.


Ahmadian, M. J., & Tavakoli, M. (2011). 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, 15(1), 35-59.
Bachman, L. F. (2004). Statistical analyses for language assessment book: Cambridge University Press.
Benevento, C., & Storch, N. (2011). Investigating writing development in secondary school learners of French. Assessing Writing, 16(2), 97-110.
Bradlow, A. R., Kim, M., & Blasingame, M. (2017). Language-independent talker-specificity in first language and second-language speech production by bilingual talkers: L1 speaking rate predicts L2 speaking rate. The Journal of the Acoustical Society of America, 141, 886–899.
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.
Cohen, L. M., & Manion, L. (1998). L.(1989) Research Methods in Education. New York: Routledge.
Ellis, R., & Barkhuizen, G. P. (2005). Analysing learner language: Oxford University Press Oxford.
Huensch, A., & Tracy–Ventura, N. (2016). Understanding second language fluency behaviour: The effects of individual differences in first language fluency, cross-linguistic differences, and proficiency over time. Applied Psycholinguistics, 38, 755– 785.
Huensch, A., & Tracy–Ventura, N. (2017). L2 utterance fluency development before, during, and after residence abroad: A multidimensional investigation. Modern Language Journal, 101, 275–293.
Hunter, A.–M. (2017). Fluency development in the ESL classroom: The impact of immediate task repetition and procedural repetition on learners’ oral fluency. (Unpublisheddoctoral dissertation). University of Surrey,Guildford, UK.
Ishikawa, T. (2006). The effect of task complexity and language proficiency on task-based language performance. Journal of Asia TEFL, 3(4).
Kim, Y., Nam, J., & Lee, S.-Y. (2016). Correlation of proficiency with complexity, accuracy, and fluency in spoken and written production: Evidence from L2 Korean. Journal of the National Council of Less Commonly Taught Languages, 19, 147-181.
Kormos, J., & Dénes, M. (2006). Exploring measures and perceptions of fluency in the speech of second language learners. System, 32, 145–164.
 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). Philadelphia/Amsterdam: John Benjamins.
Leaper, D. A., & Riazi, M. (2014). The influence of prompt on group oral tests. Language Testing, 31(2), 177-204.
Mizera, G. J. (2006). Working memory and L2 oral fluency. University of Pittsburgh,
Pallant, J. (2013). SPSS survival manual: McGraw-Hill Education (UK).
Peltonen, P. (2018). Exploring connections between first and second language fluency: A mixed methods approach. Modern Language Journal, 102, 676– 692.
Robinson, P. (2003). The cognitive hypothesis, task design, and adult task-based language learning. University of Hawai'I Second Langauge Studies Paper 21 (2).
Robinson, P. (2011). Second language task complexity: Researching the cognition hypothesis of language learning and performance (Vol. 2): John Benjamins Publishing.
Robinson, P., Cadierno, T., & Shirai, Y. (2009). Time and motion: Measuring the effects of the conceptual demands of tasks on second language speech production. Applied Linguistics, 30(4), 533-554.
Schmidt, R. (2001). Attention'in P. Robinson (ed.): Cognition and Second Language Instruction. Cambridge, UK: Cambridge University Press.
Segalowitz, N. (2010). Cognitive bases of second language fluency. New York: Routledge.
 Segalowitz, N., French, L., & Guay, J.–D. (2017). What features best characterize adult second language utterance fluency and what do they reveal about fluency gains in short-term immersion? Canadian Journal of Applied Linguistics, 20, 90–116.
Seyyedi, K., Ismail, S., & Mohamed, A. (2014). The Effect of Task Structure on Second Language Learner’s Narrative Writing Performance. Journal of Foreign Languages, Cultures and Civilizations, 2(1), 41-53.
Shiriyan, Z., & Nejadansari, D. (2014). The effect of literature-response activities on the complexity, accuracy, and fluency of Iranian EFL learners’ L2 oral productions. Journal of Applied Linguistics and Language Research, 1(2), 12-26.
Skehan, P. (1998a). A cognitive approach to language learning: Oxford University Press.
Skehan, P. (1998b). Task-based instruction. Annual review of applied linguistics, 18, 268-286.
Skehan, P. (2009a). Lexical performance by native and non-native speakers on language-learning tasks. In Vocabulary studies in first and second language acquisition (pp. 107-124): Springer.
Skehan, P. (2009b). Modelling second language performance: Integrating complexity, accuracy, fluency, and lexis. Applied linguistics, 30(4), 510-532.
Skehan, P. (2014). Limited attentional capacity, second language performance, and task-based pedagogy. Processing perspectives on task performance, 211, 211-260.
Skehan, P. (2015). Limited attention capacity and cognition. Domains and Directions in the Development of TBLT, 8, 123-155.
Skehan, P., & Foster, P. (1997). Task type and task processing conditions as influences on foreign language performance. Language teaching research, 1(3), 185-211.
Tavakoli, P., & Foster, P. (2008). Task design and L2 performance. Language Learning, 58(2), 429-473.
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, 330–349.
Yuan, F., & Ellis, R. (2003). The effects of pre‐task planning and on‐line planning on fluency, complexity and accuracy in L2 monologic oral production. Applied linguistics, 24(1), 1-27.