Abstract
In this paper, we synthesize research on the different emerging Ambient Assisted Living (AAL) sensor-based technologies and examine the spatial parameters that are used in these systems. Different lenses in examining the AAL literature are considered, such as the chronological development in sensor-based AAL and the human factors in the design of sensor-based AAL in various contexts. Relevant metrics and standards in AAL design are highlighted. A comparative prospective of these metrics and how they are applied in recent studies and systems are also discussed. The paper presents a categorization of those technologies based on their selection of the spatial information to obtain a clearer understanding of the relationship between spatial modeling and the accuracy of these technologies. Implications for the design of AAL and situated interaction in AAL contexts are discussed.