sounds. The accompanying images(Figures 1 through 6)show some of the audience reactions An advertisement sent by e-mail to all postgraduate udents at University College London invited them to participate in a study that would let them rehearse a 1 Receptive short talk(five minutes)in front of a small audience in ositive" audi a safe setting-in VR. We paid five British pounds(about nine US dollars) per subject. Those who agreed to take speaker with part completed a questionnaire designed to assess their big smiles and confidence as public speakers-the Personal Report of Confidence as a Speaker(PRCS). At the end of the study we had full data on 10 subjects. Four of the subjects had a score exceeding 10, which was the average for the group as a whole. A score exceeding 18 indicates a fear of public speak ing, so our group had relatively low levels of public speaking anxiety. The experiment employed a two- factor repeat-measures design The first factor was immersion, whether 至b 2 This intimi subjects gave their talk to the audi- dating"nega- ence displayed on a monitor or "immersed"with a head-mounted greets the display. Each subject repeated their speaker at the talk three times. The first time they beginning of a experienced either a very friendly or a very hostile audience reaction. For the second talk, subjects faced whichever audience they did not experience the first time. whether he audience was“good”or"bad” made up the second factor. The third time the audience always started off with hostile reactions, then switched into very positive reactions. We included this third time for ethical reasons and didnt use the associated data in he analysi For our experiments, we required the virtual audi- ence to convincingly emote either a pure positive or pure negative response. Audience reactions consisted of styl- ized animation scripts for individual avatars intended to convey an unambiguous evaluative message Sequences of these animations formed coherent narra tives, identical for all subjects. We devised three such 3 Theyre narratives, approximating positive, negative, and mixed listening-but audience responses not to th We didn't want entirely to automate aud lence speaker esponses, as speakers would notice if the avatars Members of the responded at completely unsuitable points during their talk. We exploited DIVE's distributed capabilities to allow an unseen operator at a remote workstation to observe the environment as an invisible avatar in the seminar room. The operator could listen to the speech as it unfolded and trigger the next audience response in he current sequence at an appropriate moment. However, only the timing, not the order, of the next audience response was at the discretion of the operator. We did this to equalize the experience across subjects in the experiment. When subjects arrived an experimenter took them to he seminar room, explained the procedures to them and asked them to supply a title fortheir talk. The exper imenter then accompanied the subjects to a nearby vr IEEE Computer Graphics and Applications Authorized licensed use limited to: SHENZHEN UNIVERSITY. Downloaded on March 27, 2010 at 06: 37: 04 EDT from IEEE Xplore. Restrictions applysounds. The accompanying images (Figures 1 through 6) show some of the audience reactions. An advertisement sent by e-mail to all postgraduate students at University College London invited them to participate in a study that would let them rehearse a short talk (five minutes) in front of a small audience in a safe setting—in VR. We paid five British pounds (about nine US dollars) per subject. Those who agreed to take part completed a questionnaire designed to assess their confidence as public speakers—the Personal Report of Confidence as a Speaker (PRCS). At the end of the study we had full data on 10 subjects. Four of the subjects had a score exceeding 10, which was the average for the group as a whole. A score exceeding 18 indicates a fear of public speak￾ing, so our group had relatively low levels of public speaking anxiety. The experiment employed a two￾factor repeat-measures design. The first factor was immersion, whether subjects gave their talk to the audi￾ence displayed on a monitor or “immersed” with a head-mounted display. Each subject repeated their talk three times. The first time they experienced either a very friendly or a very hostile audience reaction. For the second talk, subjects faced whichever audience they did not experience the first time. Whether the audience was “good” or “bad” made up the second factor. The third time the audience always started off with hostile reactions, then switched into very positive reactions. We included this third time for ethical reasons and didn’t use the associated data in the analysis. For our experiments, we required the virtual audi￾ence to convincingly emote either a pure positive or pure negative response. Audience reactions consisted of styl￾ized animation scripts for individual avatars intended to convey an unambiguous evaluative message. Sequences of these animations formed coherent narra￾tives, identical for all subjects. We devised three such narratives, approximating positive, negative, and mixed audience responses. We didn’t want entirely to automate audience responses, as speakers would notice if the avatars responded at completely unsuitable points during their talk. We exploited DIVE’s distributed capabilities to allow an unseen operator at a remote workstation to observe the environment as an invisible avatar in the seminar room. The operator could listen to the speech as it unfolded and trigger the next audience response in the current sequence at an appropriate moment. However, only the timing, not the order, of the next audience response was at the discretion of the operator. We did this to equalize the experience across subjects in the experiment. When subjects arrived, an experimenter took them to the seminar room, explained the procedures to them, and asked them to supply a title for their talk. The exper￾imenter then accompanied the subjects to a nearby VR IEEE Computer Graphics and Applications 7 1 A receptive “positive” audi￾ence greets the speaker with big smiles and lots of applause. 2 This intimi￾dating “nega￾tive” audience greets the speaker at the beginning of a presentation. 3 They’re listening—but not to the speaker. Members of the audience confer with one another. . Authorized licensed use limited to: SHENZHEN UNIVERSITY. Downloaded on March 27,2010 at 06:37:04 EDT from IEEE Xplore. Restrictions apply