Dr. René Westerholt

In recent years, a range of novel geographic datasets emerged. These originate from an ever increasing and almost pervasive integration of online technologies into our everyday lives, for instance, by using social media feeds or interacting with smart card systems. Respective data has been termed “ambient geospatial information” (AGI), because of the subtle and “unintended” ways in which people observe and report about their immediate surroundings. The outlined data sets are interesting resources for scientific research. They reflect the otherwise unobservable everyday lives of ordinary people and are partial reflections of how people interact with their contextual geography. However, AGI data sets do also differ strongly from traditional data in that their acquisition schemes and the related observations do not conform to rigorous scientific standards. Clearly, this influences the way how we can analyse and interpret these data, and it interferes with a range of assumptions that researchers typically make. For instance, in geospatial research, one important assumption is the notion of (either second-order or intrinsic) stationarity, referring to a consistent underlying data-generating process. Yet, when people perceive the environment and their personal feelings in subjective manners, this assumption is rather unrealistic and cannot provide valid grounds for analysing AGI data. Different approaches for the spatial analysis of these kinds of data are thus needed. Further, we do also need a more thorough understanding of how the AGI-related data characteristics interfere with the core functioning principles of spatial analysis methodologies. These two points are pivotal to my research agenda. More specifically, I focus on the following methodological research topics:

• the application of spatial statistics to AGI data,
• spatial analysis methodologies (e.g., Moran’s I, G-statistics),
• the role of spatial heteroscedasticity and spatial variance in AGI data,
• the conflation of spatial and platial analysis.

Research Experience

Since 2013:	Research Assistant, GIScience Research Group, Institute of Geography, Faculty of Chemistry and Earth Sciences, Heidelberg University (Germany).
10/2013 -12/2013:	Visiting Scholar, Center for Geographic Analysis, Institute for Quantiative Social Science, Harvard University, Cambridge, MA (USA).
2011-2012:	Research Assistant, Steinbeis Centre for Applied Geoinformatics and Environmental Research, Osnabrück (Germany).

Practical Experience

2011-2017:	Software Developer (mobile and web-based GIS applications), Botanical Garden, Osnabrück University (Germany).
2010-2011:	Software Developer (web-based routing application), Martin Luther University of Halle-Wittenberg (Germany).

Education

2013-2018:	Ph.D. (Dr. rer. nat.), GIScience Research Group, Institute of Geography, Faculty of Chemistry and Earth Sciences, Heidelberg University (Germany).
2010-2012:	Graduate Studies of Geoinformatics (M.Sc.), Institute for Geoinformatics and Remote Sensing, Department of Mathematics and Computer Science, Osnabrück University (Germany).
2007-2010:	Undergraduate Studies of Geoinformatics (B.Sc.), Institute for Geoinformatics and Remote Sensing, Department of Mathematics and Computer Science, Osnabrück University (Germany).

Awards and Honours

04/2018:	First Prize CDRC Data Challenge, GISRUK'18 Conference, Leicester, UK
03/2014:	Young Researchers Award 2013, North-German Society for Geoinformatics
10/2013:	International Mobility Grant Funding, German Universities Excellence Initiative II
01/2013:	PhD Scholarship, State of Baden-Württemberg

Peer-reviewed Journal Articles

Li, M., Westerholt, R. and Zipf, A. (accepted): Do people communicate about their whereabouts? Investigating the relation between user-generated text messages and Foursquare check-in places. Geo-spatial Information Science, volume and issue pending. DOI: pending.

Westerholt, R., Resch, B., Mocnik, F.-B., and Hoffmeister, D. (2018): A statistical test on the local effects of spatially structured variance. International Journal of Geographical Information Science, 32 (3), 571 - 600. DOI: 10.1080/13658816.2017.1402914.

Li, M., Westerholt, R., Fan, H. and Zipf, A. (2018): Assessing spatiotemporal predictability of LBSN: A case study of three Foursquare datasets. GeoInformatica, 22 (3), 541–561. DOI: 10.1007/s10707-016-0279-5.

Bluemke, M., Resch, B., Lechner, C., Westerholt, R. and Kolb, JP. (2017): Integrating Geographic Information into Survey Research: Current Applications, Challenges and Future Avenues. Survey Research Methods, 11 (3), 307-327. DOI: 10.18148/srm/2017.v11i3.6733.

Borgmann, P., Westerholt, R., Oevermann, S. and Zachgo, S. (2017): Webbasierte und mobile Datenerfassung im Projekt "Netzwerk zum Schutz gefährdeter Wildpflanzen in Deutschland (WIPs-De)". Natur und Landschaft, 92 (2), 69 - 75. DOI: 10.17433/2.2017.50153439.69-75.

Westerholt, R., Steiger, E., Resch, B. and Zipf, A. (2016): Abundant Topological Outliers in Social Media Data and Their Effect on Spatial Analysis. PLOS ONE, 11 (9), e0162360. DOI: 10.1371/journal.pone.0162360.

Steiger, E., Westerholt, R., Resch, B. and Zipf, A. (2015): Twitter as an indicator for whereabouts of people? Correlating Twitter with UK census data. Computers, Environment and Urban Systems, 54, 255 - 265. DOI: 10.1016/j.compenvurbsys.2015.09.007.

Westerholt, R., Resch, B. and Zipf, A. (2015): A local scale-sensitive indicator of spatial autocorrelation for assessing high- and low-value clusters in multi-scale datasets. International Journal of Geographical Information Science, 29 (5), 868-887. DOI: 10.1080/13658816.2014.1002499.
You can find a preprint ("as accepted") here.

Westerholt, R. and Resch, B. (2014): Asynchronous Geospatial Processing: An Event-Driven Push-Based Architecture for the OGC Web Processing Service. Transactions in GIS, 19 (3), 455-479. DOI: 10.1111/tgis.12104.

Conference Proceedings

Westerholt, R., Gröbe, M., Zipf, A. and Burghardt, D. (2018): Towards the statistical analysis and visualization of places. 10th International Conference on Geographic Information Science, Melbourne, Australia, DOI: 10.4230/LIPIcs.GIScience.2018.63.

Westerholt, R. (2018): The impact of the spatial superimposition of point based statistical configurations on assessing spatial autocorrelation. In: Proceedings of the 21st AGILE Conference on Geographic Information Science, Lund, Sweden.

Westerholt, R. (2017): Topological and scale-related issues in Twitter analyses through superimposed forms of spatial heterogeneity. Annual Meeting of the American Association of Geographers 2017, Boston, MA.

Borgmann, P. and Westerholt, R. (2015): Citizen Science im Botanischen Artenschutz. Dialogforum Citizen Science, German Federal Environmental Foundation, Osnabrück, Germany.

Reimer, A. and Westerholt, R. (2014): Schematization for the analysis of geolocated microblog messages. In: Proceedings of AutoCarto 2014, International Symposium on Automated Cartography, Pittsburgh, PA.

Westerholt, R., Borgmann, P. and Zimmer, B. (2012): WebMapping-basierte Erfassung pflanzengenetischer Ressourcen in der Botanik. In: Löwner, M.-O., Hillen, F. and Wohlfahrt, R. (eds.): Geoinformatik 2012 „Mobilität und Umwelt“. Aachen: Shaker-Verlag, 411 - 414.

Borgmann, P., Westerholt, R., Zimmer, B. and Zachgo, S. (2012): Einsatz eines Geoportals in der Saatguterfassung. In: Lohwasser, U., Zachgo, S. und Börner, A. (ed.): Saatguterhaltung und Nutzbarmachung von Kulturpflanzen und heimischen Wildarten. Nürtingen: Gesellschaft für Pflanzenbauwissenschaften e.V., Berichte der Gesellschaft für Pflanzenbauwissenschaften, volume 6, 17 - 19.

Book Chapters

Steiger, E., Westerholt, R. and Zipf, A. (2016): Research on social media feeds – A GIScience perspective. In: Capineri, C, Haklay, M, Huang, H, Antoniou, V, Kettunen, J, Ostermann, F and Purves, R. (eds.): European Handbook of Crowdsourced Geographic Information, London: Ubiquity Press, 237-254. DOI: 10.5334/bax.r.

Further Contributions

Borgmann, P., Westerholt, R., Oevermann, S. and Zachgo, S. (2014): WEL-Webmapping. In: Poschlod, P., Borgmann, P., Listl, D., Reisch, C. and Zachgo, S. (eds.): Handbuch Genbank WEL. Regensburg: HOPPEA Denkschriften der Regensburgischen Botanischen Gesellschaft, 133 - 140.

2018:	Places–Analysing Human Urban Experiences, Mini Conference on VGI and Social Media for Urban Planning, Z_GIS, University of Salzburg, Austria
2018:	Urban Spatial Heterogeneity – Nuisance, or Source of Information?, WISC Seminar Series, Warwick Institute for the Science of Cities, University of Warwick, Coventry, UK
2017:	Topological and scale-related issues in Twitter analyses through superimposed forms of spatial heterogeneity, Annual Meeting of the American Association of Geographers, Hynes Convention Center, Boston, MA, USA
2017:	Methodological challenges in the spatial analysis of georeferenced social media data, ABCD GIS Series, Center for Geographic Analysis, Harvard University, Cambridge, MA, USA
2016:	Mining the “big noise:“ Challenges and opportunities of social media analysis, Mapping, Sensing, and Crowdsourcing Geographic Information, Royal Geographical Society, London, UK
2016:	Spatial Analysis of Twitter Data, WISC Seminar Series, Warwick Institute for the Science of Cities, University of Warwick, Coventry, UK
2016:	The mapping portal of the GE_Sell project, Coordination Meeting GE_Sell, Federal Agency for Agriculture and Food, Bonn, Germany
2015:	Mixed-Scale Spatial Autocorrelation, Forum GI, Institute for Geoinformatics and Remote Sensing, Osnabrück University, Germany
2015:	Sampling and management of species in the national responsibility of Germany within the WIPs-De project, Dialogforum Citizen Science, German Federal Environmental Foundation, Osnabrück, Germany
2014:	Peeling the onion – multiple geographic scale levels within tweets, CrowdAnalyser Workshop 2014, Heidelberg Collaboratory for Image Processing, Heidelberg, Germany
2013:	Multi-Scale Event Detection on Twitter Tweets, Geography Colloquium, Center for Geographic Analysis, Harvard University, Cambridge, MA, USA
2012:	Using a geoportal in seed collection, Joint Congress of the Consortia for Seeds and Plant Breeding, Society for Plant Breeding, Osnabrück, Germany

2017:	Workshop: Spatial urban analytics and crowdsourced geographic information for smarter cities (convenor and session chair), Annual International Conference, Royal Geographical Society, London, UK
2015:	Workshop: CrowdAnalyser 2015 (co-organiser), Institute of Geography, Heidelberg University, Germany
2014:	Workshop: CrowdAnalyser 2014 (co-organiser), Heidelberg Collaboratory for Image Processing, Heidelberg University, Germany

2017:

Special Issue on Crowdsourcing for Urban Geoinformatics (guest editor), Geo-spatial Information Science, Taylor & Francis

WS 2017/18:	Masterclass on "Spatial Analysis" (Invited Compact Course, University of Warwick, UK)
WS 2017/18:	Introduction to the spatial analysis of human-geographic data (Lecture)
SS 2017:	Introduction to computer science for geographers (Seminar + Lab)
SS 2017:	Introduction to GIS (Lab; conception and supervision of tutors)
WS 2016/17:	Introduction to the spatial analysis of human-geographic data (Lecture)
WS 2016/17:	Spatiostatistical exploration of human-geographic data (Lab)
SS 2016:	Fundamentals of computer science for geographers (Seminar + Lab)
SS 2016:	Introduction to GIS (Lab; conception and supervision of tutors)
WS 2015/16:	Spatial associations in human geography (Lecture)

• Geo-Spatial Information Science, Taylor & Francis
• International Journal of Digital Earth, Taylor & Francis
• Journal of Location Based Services, Taylor & Francis
• Knowledge and Information Systems, Springer
• Open Geospatial Data, Software and Standards, Springer
• Transactions in GIS, John Wiley & Sons

• Royal Geographical Society, Fellow
• Association for Geoinformatics, GeoIT and Navigation, Member
• OGC, Member