Complexity accuracy and fluency in informal L2 learning among university students. Four longitudinal case studies

With English increasingly moving out of the classroom and into informal settings, studies on informal second language learning (ISLL) have supplied evidence on how prolonged exposure to informal L2 input can enhance advanced receptive and productive skills in L2 learners (Sockett 2014; Sundqvist, Sylvén 2016; Arnbjörnsdóttir, Ingvarsdóttir 2018; Dressman, Sadler 2020; Toffoli et al. 2023). However, only recently has research addressed longitudinal development within ISLL. In this respect, the three constructs of complexity, accuracy and fluency (CAF) have provided a comprehensive framework for analysing L2 learners’ acquisitional process longitudinally (Polat, Kim 2014; Kusyk 2017). CAF measures aim to assess the richness, correctness, and naturalness of learners’ L2 production and use. Furthermore, the interplay between these three dimensions across time appears to echo the non-linearity of L2 development (Ferrari 2012; Lambert, Kormos 2014; Vercellotti 2015; Michel 2017; Pallotti 2021). Starting from these premises, a longitudinal study was carried out at the University of Pavia, aiming to monitor the evolution of four participants’ L2 spoken production over time. CAF trajectories were observed through monologic storytelling tasks, investigating any possible relationship between L2 development and frequency, intensity and type of exposure to informal English input. Data analysis has revealed distinctively different profiles which appear to be affected by type and intensity of media input. It has further confirmed that L2 development is multifaceted, multi-layered and multidimensional in nature, as several individual factors, such as learners’ identity and beliefs, also play a key role in language development.