The impact of semantic mapping technique on the organization of bilingual mental lexicon and L2 utterance fluency of Iranian EFL learners

To set a scene on how second language oral fluency can be developed most effectively, the repertoire of lexical knowledge has been scrutinized for long; however, the impact of organization of the mental lexicon, concentrating on network knowledge, has yet to be explored. To this end, semantic mapping has been introduced as a technique supporting the development of already known lexical items, providing chances for restructuring the network knowledge. Accordingly, the primary aim of this study was to investigate the extent to which semantic mapping had an impact on L2 fluency of speech. This has been researched in tandem with the impact of same technique on organizational structure of mental lexicon, exploring the connectivity and strength of the connections among items stored. Finally, the relationship between organizational structure of the mental lexicon and L2 oral fluency was explored. A quantitative study was conducted with thirty-three Iranian intermediate EFL students, who were randomly divided between two groups: experimental (semantic mapping group) and control groups. Participants in both groups took part in speaking and productive word association tests in three stages of pre-tests, immediate post-tests, and after two weeks’ time interval in delayed post-tests. The experimental group participated in six-session training on semantic mapping, concentrating on practicing and retrieving the previously met lexical items, between pre-test and immediate post-test. The control group didn’t receive any training on semantic mapping while being presented with the same material as the semantic mapping group. Participants’ oral performances were analysed in terms of a range of fluency measures, reflecting on various aspects (i.e., speed, breakdown). In addition, the data collected from the word association tests was analysed regarding the overall network quality of the mental lexicon, which was used as a gauge to assess if developments in the lexical network was envisaged. The findings revealed that overall word association score increased between pre-test, immediate post-test, and also delayed post-test only for the semantic mapping group in relative to the control group. Besides, the results for various measures of oral fluency for the same group of participants indicated a similar pattern in both the immediate post-test and delayed post-test, namely a significant increase in almost all measures, except for the mean duration of silent pauses. Consequently, the results of correlational analysis showed that there is a relationship between organization of mental lexicon and fluency of speech. These findings are explained in terms of the efficacy of the technique by looking into model of L2 lexical development while inspecting the contribution of the shifts in number and strength of the connections, and finally the way strengthening the connections create an impact upon the bilingual speech production process. As such, classroom teachers ought to consider integrating this technique into their curricula to support development of knowledge of lexis and fluency of speech in L2 context