Skip to main content Accessibility help

Incidental vocabulary learning in a natural reading context: an eye-tracking study



This study responds to the call for more ecologically valid psycholinguistic research (Spivey & Cardon, 2015) by examining how readers incidentally acquire multifaceted vocabulary knowledge while reading a long, authentic text. Using eye tracking, we explore how the processing of unfamiliar words changes with repeated exposure and how the repeated exposure and processing affect word learning. In two sessions, native and non-native English speakers read five chapters of an authentic English novel containing Dari words. After reading, participants received a comprehension test and three surprise vocabulary tests. Growth curve modeling revealed a non-linear decrease in reading times that followed an S shaped curve. Number of exposures was the strongest predictor of vocabulary learning (form and meaning), while total reading time independently contributed to the learning of word meaning. Thus, both quantity and quality of lexical processing aid incremental vocabulary development and may reveal themselves differently in readers’ eye movement records.


Corresponding author

Address for correspondence: Aline Godfroid, Second Language Studies Program, B253 Wells Hall, 619 Red Cedar Road, East Lansing, MI 48824


Hide All

*This project resulted from a graduate-level seminar LLT 841 Eye-Movement Registration in Second Language Acquisition Research that took place in Fall 2014 at Michigan State University. The authors would like to thank Mostafa Papi, Jiwon Song, and Lorena Valmori for their help with data collection, Ji-Hyun Park, Megan Smith, and Le Anne Spino-Seijas for their input on the study design, and all the members of the MSU Second Language Studies Eye-Tracking Lab for their comments on earlier drafts of this paper.



Hide All
Alin, A. (2010). Multicollinearity. WIREs Computational Statistics, 2, 370374.
Anderson, S. E., Chiu, E., Huette, S., & Spivey, M. J. (2011). On the temporal dynamics of language-mediated vision and vision-mediated language. Acta Psychologica, 137 (2), 181189.
Bisson, M. J., van Heuven, W. J. B., Conklin, K., & Tunney, R. J. (2014). The role of repeated exposure to multimodal input in incidental acquisition of foreign language vocabulary. Language Learning, 64 (4), 855877.
Bruton, A., López, M. G., & Mesa, R. E. (2011). Incidental L2 vocabulary learning: An impracticable term? TESOL Quarterly, 45 (4), 759768.
Cop, U., Drieghe, D., & Duyck, W. (2015). Eye movement patterns in natural reading: A comparison of monolingual and bilingual reading of a novel. PLoS ONE, 10 (8): e0134008. doi: 10.1371/journal.pone.0134008.
Craik, F. I. M., & Lockhart, R. S. (1972). Levels of processing: A framework for memory research. Journal of Verbal Learning and Verbal Behavior, 11, 671684.
Cunnings, I. (2012). An overview of mixed-effects statistical models for second language researchers. Second Language Research, 28 (3), 369382.
Dussias, P. E. (2010). Uses of eye-tracking data in second language sentence processing research. Annual Review of Applied Linguistics, 30, 149166.
Elgort, I., & Warren, P. (2014). L2 vocabulary learning from reading: explicit and tacit lexical knowledge and the role of learner and item variables. Language Learning, 64 (2), 365414.
Ellis, N. (1994). Vocabulary acquisition: The implicit ins and outs of explicit cognitive mediation. In Ellis, N. (Ed.), Implicit and explicit learning of languages (pp. 211282). London: Academic Press.
Field, A. (2013). Discovering statistics using IBM SPSS statistics (4th ed.). London: Sage.
Folse, K. S. (2006). The effect of type of written exercise on L2 vocabulary retention. TESOL Quarterly, 40 (2), 273293.
Frenck-Mestre, C. (2005). Eye-movement recording as a tool for studying syntactic processing in a second language: A review of methodologies and experimental findings. Second Language Research, 21 (2), 175198.
Frishkoff, G. A., Perfetti, C. A., & Collins-Thompson, K. (2011). Predicting robust vocabulary growth from measures of incremental learning. Scientific Studies of Reading, 15 (1), 7191.
Gass, S. (1999). Incidental vocabulary learning. Studies in Second Language Acquisition, 21, 319333.
Godfroid, A., Boers, F., & Housen, A. (2013). An eye for words: Gauging the role of attention in incidental L2 vocabulary acquisition by means of eye tracking. Studies in Second Language Acquisition, 35, 483517.
Godfroid, A., Loewen, S., Jung, S., Park, J.-H., Gass, S., & Ellis, R. (2015). Time and untimed grammaticality judgments measure distinct types of knowledge: Evidence from eye-movement patterns. Studies in Second Language Acquisition, 37, 269–269.
Godfroid, A., & Spino, L. A. (2015). Reconceptualizing reactivity of think-alouds and eye tracking: Absence of evidence is not evidence of absence. Language Learning, 65 (4), 896928.
Godfroid, A., & Uggen, M. S. (2013). Attention to irregular verbs by beginning learners of German. Studies in Second Language Studies, 35 (2), 291322.
Godfroid, A., & Winke, P. (2015). Investigating implicit and explicit processing using L2 learners' eye-movement data. In Rebuschat, P. (Ed.), Implicit and explicit learning of languages (pp. 7390). Philadelphia, PA: John Benjamins.
Horst, M. (2005). Learning L2 vocabulary through extensive reading: A measurement study. The Canadian Modern Language Review, 61, 355382.
Horst, M., Cobb, T., & Meara, P. (1998). Beyond A Clockwork Orange: Acquiring second language vocabulary through reading. Reading in a Foreign Language, 11 (2), 207223.
Hosseini, K. (2007). A thousand splendid suns. New York: Penguin group.
Hu, M., & Nation, I. S. P. (2000). Vocabulary density and reading comprehension. Reading in a Foreign Language, 23 (1), 403430.
Hudson, T. (2015). Presenting quantitative data visually. In Plonsky, L. (Ed.), Advancing quantitative methods in second language research (pp. 78105). New York: Routledge.
Hulstijn, J. (2003). Incidental and intentional learning. In Doughty, C. & Long, M. H. (eds.), The handbook of second language acquisition (pp. 349381). Oxford: Blackwell.
Hyönä, J., & Niemi, P. (1990). Eye movements during repeated reading of a text. Acta Psychologica, 73 (3), 259280.
Joseph, H. S. S. L., Wonnacott, E., Forbes, P., & Nation, K. (2014). Becoming a written word: Eye movements reveal order of acquisition effects following incidental exposure to new words during silent reading. Cognition, 133, 238248.
Krashen, S. (1989). We acquire vocabulary and spelling by reading: Additional evidence for the input hypothesis. Modern Language Journal, 73, 440464.
Larson-Hall, J. (2017). Moving beyond the bar plot and the line graph to create informative and attractive graphics. The Modern Language Journal, 101 (1), 244270.
Laufer, B., Elder, C., Hill, K., & Congdon, P. (2004). Size and strength: Do we need both to measure vocabulary knowledge?. Language Testing, 21 (2), 202226.
Laufer, B., & Goldstein, Z. (2004). Testing vocabulary knowledge: Size, strength, and computer adaptiveness. Language Learning, 54 (3), 399436.
Laufer, B., & Hulstijn, J. (2001). Incidental vocabulary acquisition in a second language: The construct of task-induced involvement. Applied Linguistics, 22 (1), 126.
Laufer, B., & Ravenhorst-Kalovski, G. C. (2010). Lexical threshold revisited: Lexical text coverage, learners’ vocabulary size and reading comprehension. Reading in a Foreign Language, 22 (1), 1530.
Lawless, J. F. (1987). Negative binomial and mixed Poisson regression. Canadian Journal of Statistics, 15 (3), 209225.
Leow, R. P. (2015). Explicit learning in the L2 classroom. A student-centered approach. New York, NY: Routledge.
Liberman, A. M. (2005). How much more likely? The implications of odds ratios for probabilities. American Journal of Evaluation, 26 (2), 253266.
Metzner, P., von der Malsburg, T., Vasishth, S., & Rösler, F. (2016). The importance of reading naturally: Evidence from combined recordings of eye movements and electric brain potentials. Cognitive Science. Doi: 10.1111/cogs.12384
Mirman, D. (2014). Growth curve analysis and visualization using R. Boca Raton, FL: CRC Press.
Mohamed, A. (2017). Exposure frequency in L2 reading: An eye-movement perspective of incidental vocabulary learning. Studies in Second Language Acquisition. doi: 10.1017/S0272263117000092
Murre, J. M. J. (2014). S-shaped learning curves. Psychonomic Bulletin & Review, 21 (2), 344356.
Nagy, W. E., Anderson, R. C., & Herman, P. A. (1987). Learning word meanings from context during normal reading. American Educational Research Journal, 24 (2), 237270.
Nagy, W. E., Herman, P. A., & Anderson, R. C. (1985). Learning words from context. Reading Research Quarterly, 20 (2), 233253.
Nakata, T. (2015). Effects of expanding and equal spacing on second language vocabulary learning. Does gradually increasing spacing increase vocabulary learning? Studies in Second Language Acquisition, 37 (4), 677711.
Nation, I. S. P. (2012). Vocabulary Size Test information and specifications. Available from
Nation, I. S. P. (2013). Learning vocabulary in another language (2nd ed.). Cambridge: University Press.
Nation, I. S. P., & Beglar, D. (2007). Vocabulary size test. BNC version. 1–14k. Available from
Nation, I. S. P., & Webb, S. (2011). Researching and analyzing vocabulary. Boston, MA: Heinle Cengage.
Naumova, E. N., Must, A., & Laird, N. M. (2001). Tutorial in biostatistics: Evaluating the impact of ‘critical periods’ in longitudinal studies of growth using piecewise mixed effects models. International Journal of Epidemiology, 30 (6), 13321341.
Pellicer-Sánchez, A. (2015). Incidental L2 vocabulary acquisition from and while reading: An eye-tracking study. Studies in Second Language Acquisition, 38 (1), 97130.
Pellicer-Sánchez, A., & Schmitt, N. (2010). Incidental vocabulary acquisition from an authentic novel: Do things fall apart? Reading in a Foreign Language, 22 (1), 3155.
Pigada, M., & Schmitt, N. (2006). Vocabulary acquisition from extensive reading: A case study. Reading in a Foreign Language, 18 (1), 128.
Pitts, M., White, H., & Krashen, S. (1989). Acquiring second language vocabulary through reading: A replication of the Clockwork Orange study using second language acquirers. Reading in a Foreign Language, 5 (2), 271275.
Raney, G. E., & Rayner, K. (1995). Word frequency effects and eye movements during two readings of a text. Canadian Journal of Experimental Psychology, 49 (2), 151173.
program, Range (2007). Available from
Rayner, K. (1977). Understanding eye movements in reading. Scientific Studies of Reading, 1 (4), 317339.
Roberts, L. (2012). Psycholinguistic techniques and resources in second language acquisition research. Second Language Research, 28 (1), 113127.
Rott, S. (1999). The effect of exposure frequency on intermediate language learners’ incidental vocabulary acquisition and retention through reading. Studies in Second Language Acquisition, 21 (4), 589619.
Saragi, T., Nation, P., & Meister, G. (1978). Vocabulary learning and reading. System, 6, 7078.
Schmidt, R. (1990). The role of consciousness in second language learning. Applied Linguistics, 11 (2), 129158.
Schmitt, N. (2008). Review article: Instructed second language vocabulary learning. Language Teaching Research, 12 (3), 329363.
Schmitt, N. (2010). Researching vocabulary: A vocabulary research manual. London, UK: Palgrave.
Schmitt, N. (2014). Size and depth of vocabulary knowledge: What the research shows. Language Learning, 64 (4), 913951.
Sonbul, S., & Schmitt, N. (2013). Explicit and implicit lexical knowledge: Acquisition of collocations under different input conditions. Language Learning, 63 (1), 121159.
Spivey, M., & Cardon, C. (2015). Methods for studying adult bilingualism. In Schwieter, J. W. (Ed.), The Cambridge handbook of bilingual processing (pp. 108132). Cambridge, UK: Cambridge University Press.
von der Malsburg, T., & Angele, B. (2017). False positives and other statistical errors in standard analyses of eye movements in reading. Journal of Memory and Language, 94, 119133.
Waring, R., & Takaki, M. (2003). At what rate do learners learn and retain new vocabulary from reading a graded reader? Reading in a Foreign Language, 15 (2), 130163.
Webb, S. (2005). Receptive and productive vocabulary learning: The effects of reading and writing on word knowledge. Studies in Second Language Acquisition, 27 (1), 3352.
Webb, S. (2007). The effects of repetition on vocabulary knowledge. Applied Linguistics, 28 (1), 4665.
Webb, S., & Chang, A. C.-S. (2015a). How does prior word knowledge affect vocabulary learning progress in an extensive reading program? Studies in Second Language Studies, 37, 651675.
Webb, S., & Chang, A. C.-S. (2015b). Second language vocabulary learning through extensive reading with audio support: How do frequency and distribution of occurrence affect learning. Language Teaching Research, 18, 667686.
Williams, R. S., & Morris, R. K. (2004). Eye movements, word familiarity, and vocabulary acquisition. The European Journal of Cognitive Psychology, 16 (1–2), 312339.
Winke, P. M., Godfroid, A., & Gass, S. (2013). Introduction to the special issue. Eye-movement recordings in second language research. Studies in Second Language Acquisition, 35 (2), 205212.
Wochna, K. L. (2012). Comparing incidental learning of nouns and verbs using eye movements (Unpublished master's thesis). University of Illinois at Urbana-Champaign, Urbana, IL.
Zahar, R., Cobb, T., & Spada, N. (2001). Acquiring vocabulary through reading: Effect of frequency and contextual richness. Canadian Modern Language Review, 57 (3), 541572.
Zipf, G. K. (1935). The psycho-biology of language: An introduction to dynamic philology. Cambridge, MA: MIT Press.



Altmetric attention score

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed