Fingerprints of EFL writing: an AI deep learning approach

Standard methods for assessing English as a Foreign Language (EFL) writing often prioritize top-down criteria that may overlook subtle patterns and styles employed by different learners. We demonstrate a systematic and replicable three-phase approach to capture EFL writing styles using AI and data analytics, highlighting attendant insights and implications. Our approach involves (i) training a deep learning Variational Autoencoder to extract latent stylistic ‘fingerprints’ that are independent of the topic and content of writing, (ii) cluster analysis to identify emergent clusters as styles based on these fingerprints, and (iii) qualitative analysis of exemplars to interpret the styles. A case study application to EFL essays across argumentative, narrative, and reflective genres (N = 892) revealed four writing styles: 'error-prone ambition' (characterized by performative displays of advanced but contextually inappropriate vocabulary), 'striking a balance' (a more controlled approach at balancing vocabulary and grammar), 'safe and secure' (prioritizing clarity with minimal risks), and 'inconsistent expression' (deliberate or inadvertent inconsistency in stylistic choices). The clusters defining these styles have different sizes and variances, with overlapping essays hinting at underexplored developmental trajectories in EFL writing. They affirm a broader perspective where writing styles reflect not only linguistic features but also learning attitudes and strategies. Furthermore, our approach further minimizes emphasis on lexical and grammatical errors, focusing instead on stylistic regularities that can facilitate less punitive, and more nuanced and affirming ways to teach EFL writing.