For most professional tasks nowadays, it is necessary to work in teams. Such collaboration often requires the exchange of visual context-related information among the team mem- bers. For so-called shared workspace collaboration, awareness of other people's activities is of utmost importance. We have developed an augmented reality (AR) framework in or- der to support visual communication between a team of two people who are virtually co-located. We address these people as the remote user, who uses a laptop and the local user, who wears a head-mounted display (HMD) with an RGB camera. The remote user can support the local user in solving a spatial problem by providing instructions as virtual objects in the view of the local user. For placing virtual objects in the shared workspace, we use a state-of- The- Art algorithm for localization and mapping without markers. In this paper, we report on a user study that explores on how automatic audio and visual notifications about the remote user's activities affect the collaboration. The results show that in our current implementation, visual notifications are preferred over audio or no notifications independent from the level of dificulty of the task.

While augmented reality research has grown into a mature field over the last years, the aspects of situational awareness and presence of augmented reality (AR) are still quite open research topics. This paper introduces a collaborative game to explore the different perception of situational awareness and presence in a physical and an AR environment. The game is employed as an approximation of collaboratively solving complex problems. The goal of the game is to jointly build a tower with either physical blocks in a physical environment or virtual blocks in an augmented reality environment. A first study with 18 users shows the feasibility of the game and questionnaire design for studying the different perception of situational awareness and presence in a physical and an AR environment. The study further identifies necessary future research with regard to the perception of presence and awareness in AR.