Please note: This seminar will take place in DC 1304.
Géry Casiez, Professor of Computer Science
Classe Exceptionnelle, Université de Lille
Administering an independent variable within-subjects or between-subjects is a key consideration in designing any controlled experiment with human participants. We examined how this choice affects qualitative measures of embodiment in virtual reality using data from a 92-participant within-subjects study. With this dataset, we performed Monte Carlo simulations, resampling the data to mimic different sample sizes and experimental designs, to compare within- and between-subjects outcomes.
The results showed that, while reproducibility increased with the number of participants in the within-subjects simulations, the between-subjects simulations failed to reproduce the initial results, regardless of the number of participants. We discuss potential reasons that may have led to this surprising outcome and methodological practices that could mitigate these effects. More broadly, these results raise questions about how qualitative questionnaires should be administered.
Bio: Géry Casiez is a Full Professor of Computer Science, Classe Exceptionnelle, at Université de Lille. His research is in the area of Human-Computer Interaction (HCI), carried in the Loki research team, created in partnership between the Inria centre at the University of Lille and the Université de Lille within the Joint Research Unit UMR 9189 CRIStAL. Géry teaches in the CS department at IUT de Lille. His works have been published at ACM CHI, ACM UIST, IEEE VR or IHM, for which he has participated as a PC member or in the organization. In 2018, Géry was appointed junior member of the Institut Universitaire de France, became Adjunct-Professor at the University of Waterloo and deputy director of CRIStAL.
His research interests include input interaction (design of input devices, interaction techniques, study of transfer functions, latency measure and compensation, and noise reduction in interactive systems), VR and 3D interaction (study of embodiment and design of interaction techniques and input devices), interactive documents, haptics, multitouch interaction and BCI.