  With the advent of consumer-grade products for presenting an immersive
virtual environment (VE), there is a growing interest in utilizing VEs for
testing human navigation behavior. However, preparing a VE still requires a
high level of technical expertise in computer graphics and virtual reality,
posing a significant hurdle to embracing the emerging technology. To address
this issue, this paper presents Delayed Feedback based Immersive Navigation
Environment (DeFINE), a framework that allows for easy creation and
administration of navigation tasks within customizable VEs via intuitive
graphical user interfaces and simple settings files. Importantly, DeFINE has a
built-in capability to provide performance feedback to participants during an
experiment, a feature that is critically missing in other similar frameworks.
To show the usability of DeFINE from both experimentalists' and participants'
perspectives, a demonstration was made in which participants navigated to a
hidden goal location with feedback that differentially weighted speed and
accuracy of their responses. In addition, the participants evaluated DeFINE in
terms of its ease of use, required workload, and proneness to induce
cybersickness. The demonstration exemplified typical experimental manipulations
DeFINE accommodates and what types of data it can collect for characterizing
participants' task performance. With its out-of-the-box functionality and
potential customizability due to open-source licensing, DeFINE makes VEs more
accessible to many researchers.
