Present Thoughts Stephen R. Ellis Ames Research Center Moffett Field CA

1. Information Sciences & Technology Present Thoughts Stephen R. Ellis Ames Research Center Moffett Field CA • What is telepresence. • What factors influence it and where can they lead. • Does it matter whether operators of remote exploration systems feel present at the remote site? • Possible desirable characteristics of a measure of presence and of telepresence systems.

2. What is (tele)Presence? A Condition: • "... presence ... provides a rough, lumped measure of the number and fidelity of the sensory input and motor output channels” (Zeltzer, 1992) • "Presence is the extent to which a medium is perceived as sociable, warm, sensitive, personal or intimate when it is used to interact with other people” (Lombard & Ditton, 1997) A Response:* • “… presence is a subjective sensation...much like 'mental workload'... a mental manifestation not so amenable to objective physiological definition and measurement...telepresence is the sense of being physically present at the remote ... site.” (Sheridan, 1992) • ”… a sense of presence...that is the belief that [the participants] are in a world other than where there real bodies are located.” (Slater & Usoh, 1994) An Interaction • "... distal attribution [a sense of presence at the remote end of a tool] is not a necessary consequence of systematic covariation between [motor] efference and [sensory] afference, but requires as well that the observer be able to model the lawful relationship [between them]” (Loomis, 1992) • "A person is objectively present ... where the person is not physically present if there is some type of causal interaction between the person and the environment (Schloerb, 1995) • Presence is tantamount to successfully supported action in the environment" (Zahorik & Jenison, 1998; Heidegger & Gibson)

3. Presence: Many things to many people* Workload researchers see it as a concentration on the task. Attention researchers see it as a focus of attention. Situation awareness researchers see it as maximum of awareness. Controls engineers see it as arising from maximum dexterity, feedback and sensory motor fidelity. Teleconference researchers see it as a sense of sharing space with remote participants. An underlying stylistic contrast Psychological vs. Technological Anthropomorphic vs. Communication signal characteristics One central issue Can presence be usefully measured to predict performance? *Draper, Kaber, & Usher, (1998)

4. One Approach to Interpretation of Presence* Sheridan’s Analysis of Presence Equivalence Classes in Sheridan’s Analysis • *Ellis, S. R. (1996) Presence of mind: a reaction to Sheridan's musings on telepresence. Presence5, 2, 247-259.

5. Possibly Desirable Characteristics of a Telepresence System 1. Inhabitancy of Space, i.e. Spatial per-ception within virtual spaces or virtual envi-ronments is accurate. 2. Interaction Immediacy, i.e. Causal interaction with controlled elements is natural useful and efficient. 3. Motion Fluency, i.e. Controlled and uncon-trolled elements move in a smooth, co-or-dinated manner.

6. Variety of Measurement Scales Scale Property Symmetry Operation (inverse) Nominal identity Replacement (Replacement) Quality Ordinal rank Sorting (Unsorting) Equivalance class Interval unit Aggregation (Disaggregation) Quantity Ratio zero Division (Multiplication)