\chapter{Conclusion}\label{chap:conclusion}
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This thesis has addressed the subject of the use of personal user digital traces for improving human computer interaction systems. Possible strategies for the use of these traces depend on the different environments and contexts they are exploited in and through which digital technologies, either in online communities, for outdoor, contextual, indoor environments or in virtual spaces.

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\section{Summary of contribution}

As regard to outdoor spaces algorithms and systems for the identification of functional areas in cities and detection of geolocalized micro and macro-events have been presented in Chapter~\ref{chap:urban-computing-fa} and Chapter~\ref{chap:urban-computing-ed}. Recommendation, routing systems and immersive browsing interfaces for experiencing urban scenarios and to enrich itineraries visits are described in Chapter~\ref{chap:roadie} and Chapter~\ref{chap:spherical-panorama}. Improvements to standard recommenders through the exploitation of human and psychological factors, context analysis and collaborative filtering for online communities are shown in~\ref{chap:online-recomm} and in Chapter~\ref{chap:contextual-sn}. Paradigms and best practices for user analysis and context exploitation through smart portable and wearable applications are reported with several examples in Chapter~\ref{chap:smart},~\ref{chap:imaging-900} and ~\ref{chap:deep-artwork}.
New methods for the development of natural and human-centered interfaces in virtual worlds are presented and assessed with good results in Chapter~\ref{chap:locomotion} and Chapter~\ref{chap:natural-experiences}. \\
We believe that one of the main and general contributions of this thesis is that of having given an extensive overview of the different levels of digital traces needed to develop smart and at the same time adaptive systems. This adaptability has to be provided considering first of all the person who is using a technology with all his interests, behaviors and psychological concerns. Also the context in which the user is making the experience, the situation, the chronotope he is living in and his \textit{status}, permanent or momentary, are factors that cannot be disregarded.
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\section{Directions for future work}
All the studies and technologies presented in this thesis have great room for progresses both as regard to user profiling techniques and to the improvement of human computer interaction system. Dedicated directions for future work are reported at the end of each chapter. We believe, however, that the research of this thesis could really benefit in deepening arguments relating to sociology, psychology, linguistics, ergonomics and communication sciences. A synergy of these different disciplines could surely help in finding effective scope to real systems and targeted service exploiting advances in technologies such as artificial intelligence, virtual reality and natural interaction. Furthermore, from our point of view it can be stressed that a real human centered approach should register and analyze all the digital traces produced by users in a synergistic way because this is an essential point in designing adaptive, usable and effective new technologies.
}