Automatic Extraction of Urban Outdoor Perception from Geolocated Free-Texts
This work addresses the problem of scalable urban area understanding for researchers and planners by providing an incremental method to filter relevant perceptions from noisy social media data.
The authors tackled the challenge of automatically extracting urban outdoor perceptions from diverse free-text messages on location-based social networks by proposing a generic approach that exploits spatial-temporal and semantic similarity, demonstrating its effectiveness in Chicago, New York City, and London with results showing a similar level of agreement to controlled volunteer data.
The automatic extraction of urban perception shared by people on location-based social networks (LBSNs) is an important multidisciplinary research goal. One of the reasons is because it facilitates the understanding of the intrinsic characteristics of urban areas in a scalable way, helping to leverage new services. However, content shared on LBSNs is diverse, encompassing several topics, such as politics, sports, culture, religion, and urban perceptions, making the task of content extraction regarding a particular topic very challenging. Considering free-text messages shared on LBSNs, we propose an automatic and generic approach to extract people's perceptions. For that, our approach explores opinions that are spatial-temporal and semantically similar. We exemplify our approach in the context of urban outdoor areas in Chicago, New York City and London. Studying those areas, we found evidence that LBSN data brings valuable information about urban regions. To analyze and validate our outcomes, we conducted a temporal analysis to measure the results' robustness over time. We show that our approach can be helpful to better understand urban areas considering different perspectives. We also conducted a comparative analysis based on a public dataset, which contains volunteers' perceptions regarding urban areas expressed in a controlled experiment. We observe that both results yield a very similar level of agreement.