Second language acquisition (SLA) is a complex and dynamic process. Many SLA studies that have attempted to record and analyze this process have typically focused on a single modality (e.g., textual output of learners), covered only a short period of time, and/or lacked control (e.g., failed to capture every aspect of the learning process). In Project MOSLA (Moments of Second Language Acquisition), we have created a longitudinal, multimodal, multilingual, and controlled dataset by inviting participants to learn one of three target languages (Arabic, Spanish, and Chinese) from scratch over a span of two years, exclusively through online instruction, and recording every lesson using Zoom. The dataset is semi-automatically annotated with speaker/language IDs and transcripts by both human annotators and fine-tuned state-of-the-art speech models. Our experiments reveal linguistic insights into learners' proficiency development over time, as well as the potential for automatically detecting the areas of focus on the screen purely from the unannotated multimodal data. Our dataset is freely available for research purposes and can serve as a valuable resource for a wide range of applications, including but not limited to SLA, proficiency assessment, language and speech processing, pedagogy, and multimodal learning analytics.
Recent work in word sense disambiguation (WSD) utilizes encodings of the sense gloss (definition text), in addition to the input words and context, to improve performance. In this work we demonstrate that this approach can be adapted for use in multiword expression (MWE) identification by training a Bi-encoder model which uses gloss and context information to filter MWE candidates produced from a simple rule-based extraction pipeline. We achieve state-of-the-art results in MWE identification on the DiMSUM dataset, and competitive results on the PARSEME 1.1 English dataset using this method. Our model also retains most of its ability to perform WSD, demonstrating that a single model can successfully be applied to both of these tasks. Additionally, we experiment with applying Poly-encoder models to MWE identification and WSD, introducing a modified Poly-encoder architecture which outperforms the standard Poly-encoder on these tasks.
We present GrammarTagger, an open-source grammar profiler which, given an input text, identifies grammatical features useful for language education. The model architecture enables it to learn from a small amount of texts annotated with spans and their labels, which 1) enables easier and more intuitive annotation, 2) supports overlapping spans, and 3) is less prone to error propagation, compared to complex hand-crafted rules defined on constituency/dependency parses. We show that we can bootstrap a grammar profiler model with $F_1 \approx 0.6$ from only a couple hundred sentences both in English and Chinese, which can be further boosted via learning a multilingual model. With GrammarTagger, we also build Octanove Learn, a search engine of language learning materials indexed by their reading difficulty and grammatical features. The code and pretrained models are publicly available at \url{https://github.com/octanove/grammartagger}.