  Haptics in virtual reality is the emerging dimension after audiovisual
experiences. Researchers designed several handheld VR controllers to simulate
haptic experiences in virtual reality environments. Some of these devices,
equipped to deliver active force, can dynamically alter the timing and
intensity of force feedback, potentially offering a wide array of haptic
sensations. Past research primarily used a single index to evaluate how users
perceive physical property parameters, potentially limiting the assessment to
the designer's intended scope and neglecting other potential perceptual
experiences.
  Therefore, this study evaluates not how much but how humans feel a physical
property when stimuli are changed. We conducted interviews to investigate how
people feel when a haptic device changes motion impedance. We used thematic
analysis to abstract the results of the interviews and gain an understanding of
how humans attribute force feedback to a phenomenon. We also generated a
vocabulary from the themes obtained from the interviews and asked users to
evaluate force feedback using the semantic difference method. A factor analysis
was used to investigate how changing the basic elements of motion, such as
inertia, viscosity, and stiffness of the motion system, affects haptic
perception. As a result, we obtained four critical factors: size, viscosity,
weight, and flexibility factor, and clarified the correspondence between these
factors and the change of impedance.
