Hello everyone and welcome to this presentation of our research paper
"More like a person than reading text in a machine":
Characterizing User Choice of Embodied Agents vs. Conventional GUIs on Smartphones.
Best practices in user interface design suggest that
users should be given multiple ways to perform a given task.
For example, experienced users should be provided with shortcuts to frequently used features
while first-time users should be provided with step-by-step instructions or walkthroughs.
Designers should provide a virtual human interface to allow
users to carry out tasks that involve storytelling, education, or counseling.
However, given a choice between a virtual human
and a functionally equivalent conventional widget-based interface
when would users choose one over the other?
We are building health behavior change smartphone applications
that allow users to choose between a virtual human interface
and a conventional UI to carry out their tasks.
The virtual human is an Embodied Conversational Agent,
or ECA, which are animated characters that synchronize conversational behaviors with speech
to simulate face-to-face conversation
and have been shown to be effective for tasks that have
narrative or social aspects such as counseling.
However, conventional UIs may be faster for transactional or time-sensitive tasks.
In order to determine users' interface preferences we conducted a randomized
experiment where users have the option to choose between an agent and a conventional UI,
while performing health related tasks.
We hypothesized that,
the ECA would be chosen more often for the more social tasks,
and the conventional UI chosen more often for the transactional tasks,
that users who like conversational agents will choose the ECA more often than the UI
that users will choose the UI more often when facing a time constraint,
and lastly, that the users will remember more from interactions with the ECA than the UI.
We ran a 2x2 counterbalanced within-subjects experiment.
The two independent variables were task-type and constraints
The two task-types were: reporting medications, which is more transactional,
or getting recommendations for medication side-effects, which is more social.
The constraints variable was either set to being under time pressure and
potentially distracted or neither of those.
We asked each participant to perform four tasks.
A) to report medication intake without any constraints
B) to get recommendations for medication side-effects without constraints
C) to get recommendations for side-effects with a chance of being interrupted mid-task
and D) to report medication intake while under time pressure.
48 participants finished our study.
69% were female and their average age was 36 years.
We found that participants chose the UI significantly more often
than the ECA for the transactional task, that is the medication reporting,
as well as when they were under time pressure.
As a separate main-effect, participants who did not like or trust the agent
chose the UI more often than the ECA.
We conducted a semi-structured interview with participants
after they completed the four tasks.
Using a thematic analysis, we found three main themes.
The simplicity of the task and its emotional burden on the user
influenced the participants' choice of interface.
Also time and the users' environmental context are situational factors that affect this choice.
And finally, personal preferences also influence this choice
particularly among those who completed all tasks using only one interface.
As participant 25 said, quote:
"I preferred talking to her rather than reading, I just gravitated towards the agent
just because she felt more like a person than reading text in a machine."
In conclusion, we found support for our first three hypotheses.
But the fourth hypothesis on memorability was not supported.
In summary, the option of a conventional UI should be provided for quick transactional tasks
and when being under time pressure or in situations where privacy is a concern.
However, ECAs should be offered as an option for social tasks, such as storytelling, education,
or counseling especially for users who like and trust them.
Please check out our paper for more details and reach out to us for further information.
Thank you for your attention.