Title: "From Search to Predictions in Tagged Information Spaces"   ABSTRACT           
Tagging gained tremendously in popularity over past few years. When looking into the literature of tagging we find a lot of work regarding people's tagging motivation, their behavior, models that describe the folksonomy generation process, emergent semantic structures, etc., but interestingly we find quite little research showing the value of tags for searching an overloaded information space. Furthermore, there is lot of literature on the tag or item prediction problem, but interestingly almost all of them lookat the issue from a data-driven perspective. To bridge this gap in the literature, we have conducted several in-depth studies in the past showing the value of tags for lookup and exploratory search. We looked at the problem from a network theoretic and interface perspective and we will show how useful tags are for searching. Furthermore, we reviewed literature on memory processes from cognitive science and have invented a number of novel recommender algorithms based on the ACT-R and MINERVA2 theory. We will show that these approaches can not only predict tags and items extremely well, but also reveal how these models can help in explaining the recommendation processes better than current approaches.

BIOGRAPHICAL NOTE
Christoph Trattner is currently working as the head of the Social Computing Area at Know-Center, Austria's research competence for data driven business and Big Data analytics. He has a PhD (with hons), a MSc (with hons) and BSc in Computer Science and Telematics from Graz University of Technology (Austria). He recently got awarded with an ERCIM Alain Bensoussan Fellowship to work on selected topics in Social Computing in the context of BigData at NTNU in Norway. Christoph's research interests include Social and Semantic Computing, Web-Science, HCI, Recommender Systems, Networks, Data Mining and Machine Learning. In the past he was involved in various national and international research projects, either as project leader or key researcher that dealt with social semantic technologies. During the last five years in the field, he published a significant number of scientific articles in top venues and journals, e.g., JASIST, ACM WWW, IEEE SocialCom, ACM WebSci, ACM CIKM, ACM CSCW or ACM HT. He is the winner of several Best Paper/PosterAwards and Nominations. He regularly acts as a PC member on several top-tier conferences, e.g., ACM WWW, ACM HT, or UMAP and co-organizes or co-chaires a number of workshops and conferences, e.g., ACM HT, UMAP, SocialCom or i-know. At Graz University of Technology he teaches Web Science and Semantic Technologies.