Publications
論文誌 (国際) In-Vitro and In-Vivo Experiments Can Lead to Opposite Conclusions: A Consideration from a Series of Experiments on the Relationship Between Throbber Rotation Speed and Perceived Waiting Time
Takanori Komatsu (Meiji University), Shota Yamanaka, Hiroto Oshima (Meiji University), Kengo Hayashi (Meiji University)
International Journal of Human–Computer Interaction (IJHCI)
2025.5.2
Human-computer interaction studies evaluate the effectiveness of the user interface (UI) elements using either in-vitro as controlled situation or in-vivo experiments in realistic situation. Although both methods are used for comprehending complementary and multifaceted insights into the target in biology, most HCI studies usually corroborate in-vitro results with in-vivo ones. In this paper, we reported a concrete example that the results of in-vitro and in-vivo experiments were different and it was only achieved by conducting both experiments that these reasons of these discrepancies were captured. Specifically, we focused on a throbber as a target UI element and investigated how the different attributes of throbbers affect the users’ waiting time perception. The results of four in-vitro experiments showed that the throbber with slower rotational velocities was significantly perceived as being shorter. However, the results of three in-vivo experiments showed that the experimental sites displaying slower throbbers during the waiting time were significantly perceived as being longer. In fact, we could figure out that such discrepancy would be caused by users' everyday interpretations like ``A slower throbber means the network speed is slow'' that could not be assumed in in-vitro experiments. We believe that even a seemingly negative result, such as different results obtained in-vitro and in-vivo studies, can deepen the knowledge of the target UI elements. We then strongly argue that a complementary comparison of the UI elements with the findings in in-vitro and in-vivo is very important for HCI researchers.
