Researchers across disciplines use Twitter geolocation tools to filter data for desired locations. These tools have largely been trained and tested on English tweets, often originating in the United States from almost a decade ago. Despite the importance of these tools for data curation, the impact of tweet language, country of origin, and creation date on tool performance remains largely unknown. We explore these issues with Carmen, a popular tool for Twitter geolocation. To support this study we introduce Carmen 2.0, a major update which includes the incorporation of GeoNames, a gazetteer that provides much broader coverage of locations. We evaluate using two new Twitter datasets, one for multilingual, multiyear geolocation evaluation, and another for usage trends over time. We found that language, country origin, and time does impact geolocation tool performance.
Research related to automatically detecting Alzheimer’s disease (AD) is important, given the high prevalence of AD and the high cost of traditional methods. Since AD significantly affects the acoustics of spontaneous speech, speech processing and machine learning (ML) provide promising techniques for reliably detecting AD. However, speech audio may be affected by different types of background noise and it is important to understand how the noise influences the accuracy of ML models detecting AD from speech. In this paper, we study the effect of fifteen types of environmental noise from five different categories on the performance of four ML models trained with three types of acoustic representations. We perform a thorough analysis showing how ML models and acoustic features are affected by different types of acoustic noise. We show that acoustic noise is not necessarily harmful - certain types of noise are beneficial for AD detection models and help increasing accuracy by up to 4.8%. We provide recommendations on how to utilize acoustic noise in order to achieve the best performance results with the ML models deployed in real world.
In this paper, we utilize recent advancements in social media natural language processing to obtain state-of-the-art syntactic dependency parsing results for social media English. We observe performance gains of 3.4 UAS and 4.0 LAS against the previous state-of-the-art as well as less disparity between African-American and Mainstream American English dialects. We demonstrate the computational social scientific utility of this parser for the task of socially embedded entity attribute analysis: for a specified entity, derive its semantic relationships from parses’ rich syntax, and accumulate and compare them across social variables. We conduct a case study on politicized views of U.S. official Anthony Fauci during the COVID-19 pandemic.
Code-switching (CS) is a phenomenon of mixing words and phrases from multiple languages within a single sentence or conversation. The ever-growing amount of CS communication among multilingual speakers in social media has highlighted the need to adapt existing NLP products for CS speakers and lead to a rising interest in solving CS NLP tasks. A large number of contemporary approaches use synthetic CS data for training. As previous work has shown the positive effect of pretraining on high-quality CS data, the task of evaluating synthetic CS becomes crucial. In this paper, we address the task of evaluating synthetic CS in two settings. In supervised setting, we apply Hinglish finetuned models to solve the quality rating prediction task of HinglishEval competition and establish a new SOTA. In unsupervised setting, we employ the method of acceptability measures with the same models. We find that in both settings, models finetuned on CS data consistently outperform their original counterparts.
Social media platforms, such as Twitter, often provide firsthand news during the outbreak of a crisis. It is extremely essential to process these facts quickly to plan the response efforts for minimal loss. Therefore, in this paper, we present an analysis of various multimodal feature fusion techniques to analyze and classify disaster tweets into multiple crisis events via transfer learning. In our study, we utilized three image models pre-trained on ImageNet dataset and three fine-tuned language models to learn the visual and textual features of the data and combine them to make predictions. We have presented a systematic analysis of multiple intra-modal and cross-modal fusion strategies and their effect on the performance of the multimodal disaster classification system. In our experiment, we used 8,242 disaster tweets, each comprising image, and text data with five disaster event classes. The results show that the multimodal with transformer-attention mechanism and factorized bilinear pooling (FBP) for intra-modal and cross-modal feature fusion respectively achieved the best performance.
