@article{BorchertSeufertGamboaetal.2020,
  author    = {Borchert, Kathrin and Seufert, Anika and Gamboa, Edwin and Hirth, Matthias and Hoßfeld, Tobias},
  title     = {In Vitro vs In Vivo: Does the Study's Interface Design Influence Crowdsourced Video QoE?},
  series = {Quality and User Experience},
  volume    = {6},
  journal   = {Quality and User Experience},
  issn      = {2366-0139},
  doi       = {10.1007/s41233-020-00041-2},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-235586},
  year      = {2020},
  abstract  = {Evaluating the Quality of Experience (QoE) of video streaming and its influence factors has become paramount for streaming providers, as they want to maintain high satisfaction for their customers. In this context, crowdsourced user studies became a valuable tool to evaluate different factors which can affect the perceived user experience on a large scale. In general, most of these crowdsourcing studies either use, what we refer to, as an in vivo or an in vitro interface design. In vivo design means that the study participant has to rate the QoE of a video that is embedded in an application similar to a real streaming service, e.g., YouTube or Netflix. In vitro design refers to a setting, in which the video stream is separated from a specific service and thus, the video plays on a plain background. Although these interface designs vary widely, the results are often compared and generalized. In this work, we use a crowdsourcing study to investigate the influence of three interface design alternatives, an in vitro and two in vivo designs with different levels of interactiveness, on the perceived video QoE. Contrary to our expectations, the results indicate that there is no significant influence of the study's interface design in general on the video experience. Furthermore, we found that the in vivo design does not reduce the test takers' attentiveness. However, we observed that participants who interacted with the test interface reported a higher video QoE than other groups.},
  language  = {en}
}
@article{BartlWenningerWolfetal.2021,
  author    = {Bartl, Andrea and Wenninger, Stephan and Wolf, Erik and Botsch, Mario and Latoschik, Marc Erich},
  title     = {Affordable but not cheap: a case study of the effects of two 3D-reconstruction methods of virtual humans},
  series = {Frontiers in Virtual Reality},
  volume    = {2},
  journal   = {Frontiers in Virtual Reality},
  doi       = {10.3389/frvir.2021.694617},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-260492},
  year      = {2021},
  abstract  = {Realistic and lifelike 3D-reconstruction of virtual humans has various exciting and important use cases. Our and others' appearances have notable effects on ourselves and our interaction partners in virtual environments, e.g., on acceptance, preference, trust, believability, behavior (the Proteus effect), and more. Today, multiple approaches for the 3D-reconstruction of virtual humans exist. They significantly vary in terms of the degree of achievable realism, the technical complexities, and finally, the overall reconstruction costs involved. This article compares two 3D-reconstruction approaches with very different hardware requirements. The high-cost solution uses a typical complex and elaborated camera rig consisting of 94 digital single-lens reflex (DSLR) cameras. The recently developed low-cost solution uses a smartphone camera to create videos that capture multiple views of a person. Both methods use photogrammetric reconstruction and template fitting with the same template model and differ in their adaptation to the method-specific input material. Each method generates high-quality virtual humans ready to be processed, animated, and rendered by standard XR simulation and game engines such as Unreal or Unity. We compare the results of the two 3D-reconstruction methods in an immersive virtual environment against each other in a user study. Our results indicate that the virtual humans from the low-cost approach are perceived similarly to those from the high-cost approach regarding the perceived similarity to the original, human-likeness, beauty, and uncanniness, despite significant differences in the objectively measured quality. The perceived feeling of change of the own body was higher for the low-cost virtual humans. Quality differences were perceived more strongly for one's own body than for other virtual humans.},
  language  = {en}
}