\includegraphics{figures/car-itq.pdf}
\hfill
\includegraphics{figures/car-presence.pdf}
- \caption[ITQ and QT questionnaires results.]{Results of the ITQ and PQ questionnaires}
+ \caption[ITQ and QT questionnaires results.]{Results of the Immersion Tendency Questionnaire and Presence Questionnaire.}
\label{fig:carpresence}
\end{figure}
\paragraph{Discussion}
-First of all, the absence of detected difference in \emph{Immersion Tendency} between the \Tactile and \NoTactile conditions with a high p-value and small difference of means tends to indicate that there should not be a strong bias between the participant groups.
+The absence of detected difference in \emph{Immersion Tendency} between the \Tactile and \NoTactile conditions with a small difference of means and a high p-value tends to indicate that there should not be a strong bias between the participant groups.
However, this is not a definitive argument, and the problem of splitting participants into homogeneous groups is still an open question and we are currently working on it.
-Regarding our research question, we first hypothesized that tactile feedback would enhance the realism of the game.
+Regarding our research question, we first hypothesized that tactile feedback would enhance the realism of the game ($H_1$).
The results of the \emph{Realism} items of the \emph{Presence Questionnaire} support this hypothesis.
In addition to this, five participants of the \NoTactile condition explicitly reported they did not have a sensation of speed while several participants of the \Tactile condition spontaneously mentioned feeling speed.
+Our second hypothesis ($H_2$) predicted that tactile feedback would enhance the user’s sensation of \emph{Control}.
+The results do not support this hypothesis, therefore we cannot make any conclusion regarding this hypothesis.
+However, participants indeed reported control issues.
+They had difficulties to brake because they had to move their arms very close to their chest, and it was difficult to turn at the same time.
+Indeed this issue was happening in both conditions and tactile feedback did not help.
-Control
-Our second hypothesis was that the tactile feedback would enhance the user’s sensation of control. The results did not show significant effects on control items of the presence questionnaire, or dominance PAD questionnaire. However the dominance scores have a wide variance in the T condi-tion, which suggest that small effect may be detected with more users. Nevertheless we did not find support for our second hypothesis.
-The users’ comments during the experiment and discus-sions we had after the experiment gave us insights on the reasons of this result. Most of users reported difficulties to brake. They had to pull their hands close to their shoulders to break efficiently, and it was difficult to turn at the same time. This problem affected both conditions, and reflects the low overall score for control (mean 57.15/91).
-The other explanation is that the tactile feedback mapped to the direction intended to help the user to feel if the car reacted to her gestures. However we faced an interesting problem with the mapping we used. While users admitted they understood the speed information easily, they had difficulties to understand the orientation information and ignored it. When we explained this mapping to the user before the experiment, four users asked if this mapping was absolute or relative to the orientation of the hand. Our choice was to vibrate on the top side of the arm when the car was going straight, and the left or right side depending on the direction of the car (Figure 7). However usually when the user holds the imaginary wheel, the top side of the right arm faces the right of the user, and changes when the user turn the wheel. While we have no measure of this effect, this observation raises the importance of designing carefully the feedback mapped to the gestures performed by the user. More generally it is not clear if previous results on tactile cues [4,8,14,15,26] apply when the user focuses his attention to a complex task like playing a game. It led us to start a whole new study about this question, as a follow up to this work.
+%The other explanation is that the tactile feedback mapped to the direction intended to help the user to feel if the car reacted to her gestures. However we faced an interesting problem with the mapping we used. While users admitted they understood the speed information easily, they had difficulties to understand the orientation information and ignored it. When we explained this mapping to the user before the experiment, four users asked if this mapping was absolute or relative to the orientation of the hand. Our choice was to vibrate on the top side of the arm when the car was going straight, and the left or right side depending on the direction of the car (Figure 7). However usually when the user holds the imaginary wheel, the top side of the right arm faces the right of the user, and changes when the user turn the wheel. While we have no measure of this effect, this observation raises the importance of designing carefully the feedback mapped to the gestures performed by the user. More generally it is not clear if previous results on tactile cues [4,8,14,15,26] apply when the user focuses his attention to a complex task like playing a game. It led us to start a whole new study about this question, as a follow up to this work.
-General discussion
-Besides our hypotheses, we gathered various interesting remarks. Users showed interest in the tactile feedback, and suggested other mappings that they would like to have. Several users requested vibrations when they hit obstacles. While we believe this kind of feedback is interesting, it is already used in current console games with vibrating gamepads. We decided to not include existing feedback in this study to explore new kinds of feedback. One of the participants, used to play car games, would like a feedback for the accelerations (G). He believes it would add realism, sensation of speed, and help him to turn correctly. Another participant, not used to play videogames but expert in HCI, suggested providing tactile feedback more sparsely. His point is that it would make the feedback more noticeable, and the user would seek for the feedback.
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-%, significant difference in sensory and realism factors.
-
- => travaux embodiment
-
-%Distal touch
+%General discussion
+%Besides our hypotheses, we gathered various interesting remarks. Users showed interest in the tactile feedback, and suggested other mappings that they would like to have. Several users requested vibrations when they hit obstacles. While we believe this kind of feedback is interesting, it is already used in current console games with vibrating gamepads. We decided to not include existing feedback in this study to explore new kinds of feedback. One of the participants, used to play car games, would like a feedback for the accelerations (G). He believes it would add realism, sensation of speed, and help him to turn correctly. Another participant, not used to play videogames but expert in HCI, suggested providing tactile feedback more sparsely. His point is that it would make the feedback more noticeable, and the user would seek for the feedback.
\subsection{Discussion}
-The paradox here is that the motivation for 3D gestural interaction was to offer users \emph{natural} ways to interact with systems, without manipulating artificial artifacts.
-However without haptic sensations, the virtual objects manipulated do not feel real to users, and they struggle to to manipulate them.
-Restoring haptic feedback on dwell buttons was not sufficient to make them efficient.
-3s min for clicking a button, large buttons in expe, etc.
-
-
-focus on feedback rather than interaction
-
- => Travaux direct manipulation
-
-qualitative properties taht did not necessarily match the task
-
- => travaux embodiment
+The paradox here is that the motivation for 3D gestural interaction was to offer users \emph{natural} ways to interact with systems, without manipulating artificial artifacts.
+Whether if it was relevant or not, without haptic sensations the virtual objects manipulated do not feel real to users, and they sometimes struggle to to manipulate them.
+Restoring haptic feedback on dwell buttons was not sufficient to make them efficient.
+My hypothesis was that restoring tactile feedback would help users press them.
+I anticipated that this would increase selection performance.
+However, with the way I emplemented these buttons activation required at least \SI{3}{\s}.
+This is very long indeed.
+Should tactile feedback help selecting buttons faster, the effect size could not be sufficient to make a significant improvement.
+The average selection time in the \NoTactile condition was \SI{3.6}{\s}, and it was \SI{3.5}{\s} in the \Tactile.
+This is a first clue that improving haptic feedback is not sufficient.
+It requires an efficient input method as well, otherwise the eventual benefits of haptics do not compensate the inefficiency of input.
+In \refsec{sec:hapticparadigms} I describe a new paradigm for 3D gestural interaction with haptic feedback, and the systematic design of both the input and output vocabulary to enable direct manipulation on a tactile display.
+
+% > summary(time$DwellTime[time$Condition == "NoTactile"])
+% Min. 1st Qu. Median Mean 3rd Qu. Max.
+% 3070 3110 3130 3617 3605 23270
+% > summary(time$DwellTime[time$Condition == "Tactile"])
+% Min. 1st Qu. Median Mean 3rd Qu. Max.
+% 3070 3110 3130 3582 3358 23320
+
+The qualitative study with the car racing scenario showed a similar issue.
+Tactile feedback did provide qualitative benefits.
+However the low quality of inputs diluted these benefits and made them barely measurable.
+The haptic feedback provided was questionable as well.
+I used spatial location around the wrist, however the task required participants to rotate their wrist.
+Therefore it might have influenced negatively on how participants interpreted the tactile cues.
+Unfortunately I did not investigate this issue at the time.
+Moreover the haptic cues inducated the steering angle of the wheel, not the car.
+The rationale is that it provides users immediate feedback of their actions, which is lacking without a physical controller.
+However it does not provide haptic feedback about the result of the action.
+Regrettably, I did not investigate this aspect neither.
+On the positive side I did measure an effect of tactile feedback on presence.
+This is an interesting result for the Virtual Reality community, and I regret this result was not published in the end, hence the discussion here.
+However, later we investigated a related question with the effect of haptic feedback on the sense of embodiment, which we will discuss in \refsec{sec:embodiment}.
\section{Modeling humans and interactive systems}
\section{Case studies}
\subsection{Haptic interaction paradigms}
-
-Direct Manipulation~\cite{gupta16,gupta16a}
-\label{sec:hapticdm}
-
-Direct manipulation is one of the most fundamental foundation of GUIs~\cite{schneiderman83}.
-It provides valuable usability benefits that highly contributed to the success of GUIs over command line interfaces.
-Yet, the description of this paradigm relied essentially on visual cues.
-In this project, we explained how to adapt the concept of direct manipulation to tactile displays.
+\label{sec:hapticparadigms}
Summon interactions~\cite{gupta17}
\label{sec:summon}
Therefore the user is always potentially interacting with the environment.
This is known as the Midas touch problem, as a reference to the Midas king in the greek mythology, who turned everything he was touching to gold.
+Direct Manipulation~\cite{gupta16,gupta16a}
+\label{sec:hapticdm}
+
+Direct manipulation is one of the most fundamental foundation of GUIs~\cite{schneiderman83}.
+It provides valuable usability benefits that highly contributed to the success of GUIs over command line interfaces.
+Yet, the description of this paradigm relied essentially on visual cues.
+In this project, we explained how to adapt the concept of direct manipulation to tactile displays.
+
\subsection{Haptic and embodiment in Virtual Reality}
projects / hdr.git / commitdiff