Situated interaction on spatial topics

The interaction on spatial topics is highly important no only in the context of mobile and situated systems but also in other fields such as natural language access to maps or user interfaces. Therefore, one goal of this thesis is to develop a generic model for situated interaction on spatial topics that can be used to build real world applications. In addition, we analyze typical problems that arise in the context of mobile real world applications, and point out strategies for coping with them. In order to provide background information, we first review basic concepts and definitions from the field of spatial reasoning as well as from the modeling of situations and tasks, and highlight their relationship. This discussions includes topics such as scale, spatial frames of reference and relations as well as user and context models. Then, we review a selection of related work in the context of navigational assistance, and analyze their advantages and shortcomings with respect to the goal of this thesis. This comparison also includes the prototypical implementation of the approach presented hereafter. Based on this analysis, we present an approach for the modeling of situated interaction on spatial topics in the main part of this work. This model incorporates several features that go beyond previous approaches: Situational factors – such as contextor user-related factors – are taken into account at the lowest level with respect to the current task. We designed the model in a way that supports the inclusion of further factors and the adaptation of their impact in context of a specific task. An additional noteworthy feature is the underlying systematic analysis of induced frames of reference. Furthermore, the model is highly modular and therefore facilitates the modeling of complex task by combining partial models for basic processes and/or other complex tasks. It incorporates components for the evaluation of objects in the context of a specific task and situation, for the establishment of spatial frames of reference, for the computation of twoand n-point relations as well as for the segmentation of complex trajectories. In addition, our approach relies on a representation for spatial interaction that is largely independent of the target language or modality. We used this format to encode all interactions between the user and the system. The second major contribution of this thesis consists of a set of adaptation strategies for systems that allow for situated interaction on spatial topics in a the real world setting. We first introduce means to address the lack of information as well as resource restrictions within the previously presented model. Due to the general relevance of positional information in the context of systems that are aware of the current situation, we then present a comprehensive approach to determine and process the positional information. The corresponding strategies include approaches based