The Impact of Task Complexity along Single Task Dimension on EFL Iranian Learners' Written Production: Lexical complexity

Document Type: Research Paper


English Language Department, Islamic AZAD University, Zanjan branch, Zanjan, Iran


Based on Robinson’s Cognition Hypothesis, this study explored the effects of task complexity on the lexical complexity of Iranian EFL students’ argumentative writing.This study was designed to explore the manipulation of cognitive task complexity along +/-single task dimension (a resource dispersing dimension in Robinson’s triadic framework) on Iranian EFL learners’ production in term of lexical complexity. To this end, based on the results of the writing test of TOFEL (2004), 48 learners were selected and assigned to two groups, simple task group (STG, n = 24) and complex task group (CTG, n= 24) randomly. The participants in the STG were given an eight-frame picture which had been arranged in the correct sequence before its administration (+single task). These participants were required to order the frames in the right sequence first, before starting writing (- single task). Their output was encoded based on the measures of lexical complexity. The null hypothesis was nullified since the results indicated positive significant impact of +/-single dimension on lexical complexity. Regarding the results of the present study, it can be stated that when the participants were engaged putting the pictures in their correct order in the complex task, they carried out deeper semantic processing in order to find the reasonable order, which might lead to the better activation of their exemplar-based system and made them browse it more deeply. It was found that, at least in the Iranian context, Robinson’s (2005) predictions were more convincing.


Abdollahzadeh, S. & Fard Kashani, K. (2012). The effect of task complexity on EFL learners’ narrative writing task performance. Journal of English Language Teaching and Learning, 8, 1-28.
Attarzade, S., & Farahani, E. (2014). The effect of task complexity on Iranian EFL learners’ listening comprehension across aptitude. Procedia - Social and Behavioral Sciences, 98, 314 – 323.
Bachman, L. F. (1990). Fundamental consideration in language testing. Oxford: Oxford University Press.
Bachman, L. F., & Palmer, A.S. (1996). Language testing in practice. Oxford: Oxford University Press.
Breen, M. (1989). The evaluation of cycle for language learning asks. In R. K. Johnson (Ed.), The second language curriculum (pp. 187–206). Cambridge: Cambridge University Press.
Berwick, R. (1993). Toward an educational framework for teacher-led tasks. In G. Crookes & S. Gass (Eds.), Tasks in a pedagogical context: Integrating theory and practice (pp. 97-124). Clevedon: Multilingual Matters.
Brown, H. D. (2000). Principles of language learning and teaching. (4th Ed.). London: Addison Wesley Longman, Inc.
Brown, G., Anderson, A., Shilcock, R., & Yule, G. (1984). Teaching talk: Strategies for production and assessment. Cambridge: Cambridge University Press.
Brown, G., & Yule, G. (1983). Discourse analysis. New York: Cambridge University Press.
Bygate, M. (1999). Task as the context for the framing, re-framing and un-framing of language. System, 27(1), 33-48.
Bygate, M., Skehan, P., & Swain, M. (Eds.) (2001). Researching pedagogic tasks: Second language learning, teaching and testing. Harlow: Pearson Education Limited.
Cooper, L. (1984). The assessment of writing ability: A review of research. GRE Board Research Report GREB No. 82-15, ETS Research Report. Princeton: ETS: Retrieved January 16, 2015 from
Corder, S. P. (1981). Error analysis and interlanguage. Oxford: Oxford University Press.
Crookes, G. (1986). Task classification: a cross-disciplinary review. Center for Second Language Classroom Research, Social Science Research Institute: University of Hawaii Press.
Crookes, G. (1989). Planning and interlanguage variation. Studies in Second Language Acquisition, 11(4), 367-383.
Ellis, R. (1987). Interlanguage variability in narrative discourse: Style shifting in the use of the past tense. Studies in Second Language Acquisition, 9, 1-20.
Ellis, R. (2003). Task based language learning and teaching. Oxford: Oxford University Press.
Ellis, R. (2008). The study of second language acquisition (2nd Ed.). Oxford: Oxford University Press.
Ellis, R., & Yuan, F. (2004). The effects of planning on fluency, complexity, and accuracy in second language narrative writing. Studies in Second Language Acquisition, 26(1), 59-84.
Farahani, A. K., & Meraji, S. R. (2011). Cognitive task complexity and L2 narrative writing performance. Journal of Language Teaching and Research, 2(2), 445-456.
Foster, P. & Skehan, P. (1996). The influence of planning and task type on second language performance. Studies in Second Language Acquisition, 18, 299-323.
Foster, P. & Skehan, P. (1999). The influence of planning and focus of planning on task-based performance. Language Teaching Research, 3, 215-247.
Gilabert, R. (2004). Task complexity and L2 narrative oral production. Unpublished doctoral dissertation, University of Barcelona-Barcelona, Spain. Retrieved April 23, 2015 from
Gilabert, R. (2007). The simultaneous manipulation of task complexity along planning time and [+/-Here-and-Now]: Effects on L2 oral production. In M. del Pilar Garcia-Mayo (Ed.), Investigating tasks in formal language learning (pp. 44-68). Clevedon, Avon: Multilingual Matters.
Givon, T. (1985). Function, structure, and language acquisition. In D. Slobin (Ed.), The crosslinguistic study of language acquisition (pp. 1008-1025). Hillsdale, NJ: Lawrence Erlbaum.
Hulstijn, J. H., & Schmidt, R. (1994). Deconstructing consciousness in search of useful definitions for applied linguistics. AILA Review, 1(1), 11-26.
Ishikawa, T. (2007). The effect of manipulating task complexity along the [+/- Here- and-Now] Dimension on L2 written narrative discourse. In M. del Pilar Garcia-Mayo (Ed.), Investigating tasks in formal language learning (pp. 136-156). Clevedon, Avon: Multilingual Matters.
Iwashita, N., Elder, C., & McNamara, T. (2001). Can we predict task difficulty in an oral proficiency test? Exploring the potential of an information-processing approach to task design. Language Learning, 51(3), 401-436.
Jiaxin, X. I. N. G. (2015). The effects of increasing task complexity on EFL learners’ writing performance. Studies in Literature and Language11(4), 34-39.
Kawauchi, C. (2005). The effects of strategic planning on the oral narratives of learners with low and high intermediate L2 proficiency. In R. Ellis (Ed.), Planning and task performance (pp. 143-164). Amsterdam/ Philadelphia: John Benjamins.
Kormos, J., & Trebits, A. (2012). The role of task complexity, modality, and aptitude in narrative task performance. Language Learning62(2), 439-472.
Larsen-Freeman, D. (2006). The emergence of complexity, fluency, and accuracy in the oral and written production of five Chinese learners of English. Applied Linguistics 27(4), 590–619.
Lee, J. (2000). Tasks and communicating in language classrooms. Boston: McGraw-Hill.
Levelt, W. (1989). Speaking: from intention to articulation. Cambridge: Cambridge University Press.
Long, M. H. (1985). A role for instruction in second language acquisition: task-based language teaching. In K. Hyltenstam & M. Pienemann (Eds.), Modelling and assessing second language acquisition (pp. 77-99). Clevedon: Multilingual Matters.
Mehrinejad, M. Z., & Aliasin, S. H. (2015). The Impact of Task Complexity on Iranian EFL Learners’ L2 Reading Comprehension. Journal of Applied Linguistics and Language Research2(4), 285-294.
Mohammadzadeh, M. A., Dabaghi, A., & Tavakoli, M. (2013). The effects of simultaneous use of pre-planning along +/-here-and-now dimension on fluency, complexity and accuracy of Iranian EFL learners’ written performance. International Journal of Research Studies in Language Learning, 2(3), 49-65.
Masrom, U. K., Daud, N. S. M., & Alwi, N. A. N. M. (2015). Task complexity and the complexity of written language production: A review of literature. International Journal of Linguistics7(3), 78-93.
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.
Nunan, D. (1989). Designing tasks for the communicative classroom. Cambridge: Cambridge University Press.
Prabhu, N. S. (1987). Second language pedagogy. Oxford: Oxford University Press.
Rahimpour, M. (2007). Task complexity and variation in L2 learners’ oral discourse. University   of Queensland Working Papers in Linguistics, Retrieved April 23, 2015 from
Richards, J., Platt, J., & Weber, H. (1985). Longman dictionary of applied linguistics. Longman: Longman
RimaniNikou, F., & Eskandarsefat, Z. (2012). The simultaneous effects of task complexity and task types on EFL learners’ written performance. Australian Journal of Basic and Applied Sciences, 6(7), 137-143.
Robinson, P. (1995a). Review article, attention, memory, and the ‘noticing’ hypothesis. Language Learning, 45(2), 283-331.
Robinson, P. (1995b). Task complexity and second language narrative discourse. Language Learning, 45(1), 99-140.
Robinson, P. (2001a). Task complexity, task difficulty, and task production: Exploring interactions in a componential framework. Applied Linguistics, 22(1),27-57.
Robinson, P. (2001b). Task complexity, cognition resources, and syllabus design: a triadic framework for examining task influences on SLA. In P. Robinson (Ed.), Cognition and second language instruction (pp. 287-318).Cambridge: Cambridge University Press.
Robinson, P. (2003). The cognition hypothesis, task design, and adult task-based language learning. Second Language Studies, 21(2), 45-105.
Robinson, P. (2005). Cognitive complexity and task sequencing: Studies in a componential framework for second language task design. Annual Review of Applied Linguistics, 43(1), 1-32.
Robinson, P. (2007a). Criteria for classifying and sequencing pedagogic tasks. In M. del Pilar Garcia-Mayo (Ed.), Investigating tasks in formal language learning (pp. 7-26). Clevedon, Avon: Multilingual Matters.
Robinson, P. (2007b). 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, 45, 193-213.
Rouhi, A., & Marefat, H. (2006). Planning time effect on fluency, complexity and accuracy of L2 output. Pazhuhesh-e zabanha-ye Khareji, 27, 123-141.
Salimi, A., Dadaspour, S., & Asadollahfam, H. (2011). The effect of task complexity on EFL learners’ written performance. Social and Behavioral Sciences, 29, 1390 – 1399.
Schmidt, R. (1990). The role of consciousness in second language learning. Applied Linguistic, 11(2), 17-46.
Schmidt, R. (2001). Attention. In P. Robinson (Ed.), Cognition and second language instruction Cambridge: Cambridge University Press.
Skehan, P. (1996). A framework for the implementation of task-based instruction. Applied Linguistics, 17(1), 38-62.
Skehan, P. (1998). A cognitive approach to language learning. Oxford: Oxford University Press.
Skehan, P. (2003). Task-based instruction. Language Teaching, 36, 1-14.
Skehan, P., & Foster, P. (1997). Task type and task processing conditions as influences on foreign language performance. Language Teaching Research, 1(3), 185-211.
Skehan, P., & Foster, P. (1999).The influence of task structure and processing conditions on narrative retellings. Language Learning, 49(1), 93-120.
Skehan, P., & Foster, P. (2001). Cognition and tasks. In P. Robinson (Ed.), Cognition and second language instruction (pp. 183-205).Cambridge: Cambridge University Press.
Swales, J. (1990). Genre analysis. Cambridge: Cambridge University Press.
Sotoudehnama, E., & Farahanynia, M. (2014). Cognitive task complexity and Iranian EFL learners’ written linguistic performance across writing proficiency levels. The Journal of Teaching Language Skills, 6(2), 107-128.
Tavakoli, P., & Skehan, P. (2005). Strategic planning, task structure, and performance testing. In R. Ellis (Ed.), Planning and task performance (pp. 239-213). Amsterdam/Philadelphia: John Benjamins Publishing Company
van Patten, B. (1990). Attending to form and content in the input: An experiment in consciousness. Studies in Second Language Acquisition, 12, 287-301.
van Patten, B. (1996). Input processing and grammar instruction in second language acquisition. Norwood, N.J.: Ablex Publishing.
van Patten, B. (2002). Processing instruction: An update. Language Learning, 52(4), 755-803.
van Waes, L., & Leijten, M. (2015). Fluency in writing: A multidimensional perspective on writing fluency applied to L1 and L2. Computers and Composition38, 79-95.