Wednesday, June 10, 2020

New Paper: A Thematic Similarity Network Approach for Analysis of Places Using VGI

Building upon our work on volunteered geographical information (VGI) and ambient geographic information (AGI) and how such data (e.g. social media) can be used to understand place, Xiaoyi Yuan, Andreas Züfle and myself have a new paper entitled: "A Thematic Similarity Network Approach for Analysis of Places Using Volunteered Geographic Information" in the ISPRS International Journal of Geo-InformationIn this paper we use textual data from crowdsourced reviews originating with TripAdvisor and geo-located Twitter data and leverage this unstructured geographical information to comprehend the complexity of places at scale. Specifically we explore the connectedness and relationships of places through thematic (i.e., topical) similarity networks using Manhattan, New York as a case study. If such work sounds of interest to you, below we provide the abstract to the paper in order for you to gain a greater understanding of work, along with some figures that show our workflow and how communities where connected, before presenting some of our results. Finally at the bottom of the post, the full reference and a link to the paper is provided.  For those interested in extending or utilizing this work. The python code for presented in our analysis is available at: https://bitbucket.org/xiaoyiyuan/network_vgi/

Abstract:
The research presented in this paper proposes a thematic network approach to explore rich relationships between places. We connect places in networks through their thematic similarities by applying topic modeling to the textual volunteered geographic information (VGI) pertaining to the places. The network approach enhances previous research involving place clustering using geo-textual information, which often simplifies relationships between places to be either in-cluster or out-of-cluster. To demonstrate our approach, we use as a case study in Manhattan (New York) that compares networks constructed from three different geo-textural data sources --TripAdvisor attraction reviews, TripAdvisor restaurant reviews, and Twitter data. The results showcase how the thematic similarity network approach enables us to conduct clustering analysis as well as node-to-node and node-to-cluster analysis, which is fruitful for understanding how places are connected through individuals’ experiences. Furthermore, by enriching the networks with geodemographic information as node attributes, we discovered that some low-income communities in Manhattan have distinctive restaurant cultures. Even though geolocated tweets are not always related to place they are posted from, our case study demonstrates that topic modeling is an efficient method to filter out the place-irrelevant tweets and therefore refining how of places can be studied.

Keywords: Geo-Textual Data, Volunteered Geographic Information, Crowdsourcing, Similarity Network Analysis, Topic Modeling

Work flow from data input to the construction of the thematic similarity network and analysis (i.e., community detection and unique nodes discovery).

A stylized network demonstrating the process of community detection from a fully-connected similarity network.


Network visualization of all communities from the thematic similarity networks with major communities highlighted. Only the major communities are shown on the map for the sake of clarity. Major communities in Network visualization and mapping for each network are colored the same and thus the legend applies for both.


Two examples of communities with boundary nodes and their respective topics.

Full Reference:
Yuan X., Crooks, A.T. and Z├╝fle, A. (2020), A Thematic Similarity Network Approach for Analysis of Places Using Volunteered Geographic Information, ISPRS International Journal of Geo-Information,  9(6), 385, https://doi.org/10.3390/ijgi9060385. (pdf)

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