MORSE: MultimOdal sentiment analysis for Real-life SEttings

Multimodal sentiment analysis aims to detect and classify sentiment expressed in multimodal data. Research to date has focused on datasets with a large number of training samples, manual transcriptions, and nearly-balanced sentiment labels. However, data collection in real settings often leads to small datasets with noisy transcriptions and imbalanced label distributions, which are therefore significantly more challenging than in controlled settings. In this work, we introduce MORSE, a domain-specific dataset for MultimOdal sentiment analysis in Real-life SEttings. The dataset consists of 2,787 video clips extracted from 49 interviews with panelists in a product usage study, with each clip annotated for positive, negative, or neutral sentiment. The characteristics of MORSE include noisy transcriptions from raw videos, naturally imbalanced label distribution, and scarcity of minority labels. To address the challenging real-life settings in MORSE, we propose a novel two-step fine-tuning method for multimodal sentiment classification using transfer learning and the Transformer model architecture; our method starts with a pre-trained language model and one step of fine-tuning on the language modality, followed by the second step of joint fine-tuning that incorporates the visual and audio modalities. Experimental results show that while MORSE is challenging for various baseline models such as SVM and Transformer, our two-step fine-tuning method is able to capture the dataset characteristics and effectively address the challenges. Our method outperforms related work that uses both single and multiple modalities in the same transfer learning settings.