# Telepresence Social Robotics towards Co-Presence: A Review
## 2 Co-Presence Taxonomy  
_Social presence_ has been defined as the _sense of being together with another_, which includes primitive reactions to social cues and automatic creation of simulations or mental models of \"_other minds_\" [13]. [PERSON] et al. [12] defined _social presence_ as \"the degree of salience of the other person in the interaction and the consequent salience of the interpersonal relationship\". _Co-presence_ is a different concept, introduced by [PERSON] [26] to describe the active state in which a person perceives his or her interlocutor, and the interlocutor also perceives him or her. _Copresence_ refers to a \"psychological connection to and with another person\", in which \"interactants feel they were able to perceive their interaction partner and that their interaction partner actively perceived them\" [17]. With co-presence being a subjective concept, it involves different dimensions and interpretations depending on the social science discipline and application area (e.g., sociology or psychology) [18; 29; 30]. _Social presence_ appears in the literature as being related to the _quality of the communication's medium_[12] and the user's perception of the medium. Therefore, preliminary studies have focused on the effect of modality on social presence. They identified potential predictors of social presence by analyzing the technology's capability to reproduce social cues (e.g., visual representation, audio, and haptic feedback). The findings were biased by the considered concept definitions. Some predictors contribute directly to presence, co-presence, or social presence, while others affect them indirectly by acting on a person's involvement and immersion. Therefore, it is important to distinguish the \"immersion\" concept and the \"presence\" concept [15; 34]. _Immersion_, also known as _sensorimotor immersion_, refers to the extent and fidelity of physical stimulation affecting the human sensory systems and the system's responsiveness  
Figure 2: (**a**) Article’s citation distribution per main topic, (**b**) per _Co-Presence Taxonomy_ / _Preditors_ topic, (**c**) per _From Telepresence to Co-Presence Design_ topic, and (**d**) the article’s citation distribution per year. to the motor inputs. The immersive level depends on the number and range of sensors and the motor channels connected to a remote agent in a real environment (e.g., a robot) or to a mediated virtual environment. Immersion is determined by the naturalness and coherence between actions (head, body, and gesture movements) and the expected sensory feedback [35; 36; 37; 38]. _Presence_ is the psychological product of technological immersion, defined as _the perceptual illusion of non-mediation_[39] or simply referred to as the sense of _being there_ in a mediated virtual environment [15; 34]. [PERSON] [16] differentiates presence (virtual) from telepresence (experiential), in which _presence_ describes the experience of being present within a virtual world while _telepresence_ refers to the sense of being in a mediated remote real environment [19; 40]. _Co-presence_ has been used to refer to the _sense of being together_ with others in a mediated environment, either remote real or virtual [18; 41]. As described in the definitions, the use of concepts such as co-presence and social presence should not be confused as they are assessed differently [17]. In the context of social robotics, there are agents with autonomous and semi-autonomous behaviors that are seen by the local person as the \"other\". Additionally, some agents simply mediate the communications between two persons (the remote and local users). In the former case, the sense of co-presence is assessed between an artificial system and a person, while in the second scenario, co-presence involves two humans. Typically, in robotic telepresence, the representation of the remote real person is shaped by the technology that mediates communication. This affects the perception of thoughts and emotions when compared with actual face-to-face (FtF) interaction.