![](bga.png)
all answers got higher marks on average. This as-
sesses the potential of this approach. Nevertheless,
the command-based human-agent interaction still ap-
peared as the weakest feature.
7 CONCLUSIONS
In this paper we have explicitly structured partici-
pants’ interactions in hybrid (humans and software
agents) virtual environments (VE). We have presented
an example scenario in an e-government application
(v-mWater, a virtual market based on trading Water),
and evaluated its usability. We have also described
the execution infrastructure that supports this hybrid
and structured scenario where humans and bots inter-
act both each other and with the environment. Fur-
thermore, we characterize different interaction mech-
anisms and provide human users with multi-modal
(visual, gestural and textual) interaction. In our us-
ability study, we have paid special attention to how
users perceive their interaction with bots.
The usability evaluation results provide an early
feedback on the implemented scenario. v-mWater is
perceived as a useful and powerful application that
could facilitate everyday tasks in the future. Users
like its learnability, its immersiveness, and how sce-
nario settings facilitate task accomplishment. In gen-
eral, users have well completed the proposed task and
were able to go to the right destination in the sce-
nario. After doing the test, users improved their opin-
ion about 3D VEs. In addition, the overall opinion of
the human-bot interaction is positive.
Nevertheless, there are some inherent limitations
of interface dialogs and interactions. Some users are
not comfortable using the command-based bot dia-
log and find difficult to move their avatar in the 3D
VE. Thus, a future research direction is to define new
forms of human-bot interactions, using multimodal
techniques based on voice, or sounds and tactile feed-
back supported by gaming devices. We also plan to
incorporate assistant agents to help humans partici-
pate effectively in the system, and perform a compar-
ative usability study to assess assistants’ utility.
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