How Much Control Is Enough? Influence of Unreliable Input on User Experience

Abstract

Brain–computer interfaces (BCI) provide a valuable new input modality within human–computer interaction systems. However, like other body-based inputs such as gesture or gaze based systems, the system recognition of input commands is still far from perfect. This raises important questions, such as what level of control should such an interface be able to provide. What is the relationship between actual and perceived control? And in the case of applications for entertainment in which fun is an important part of user experience, should we even aim for the highest level of control, or is the optimum elsewhere? In this paper, we evaluate whether we can modulate the amount of control and if a game can be fun with less than perfect control. In the experiment users (n = 158) played a simple game in which a hamster has to be guided to the exit of a maze. The amount of control the user has over the hamster is varied. The variation of control through confusion matrices makes it possible to simulate the experience of using a BCI, while using the traditional keyboard for input. After each session the user completed a short questionnaire on user experience and perceived control. Analysis of the data showed that the perceived control of the user could largely be explained by the amount of control in the respective session. As expected, user frustration decreases with increasing control. Moreover, the results indicate that the relation between fun and control is not linear. Although at lower levels of control fun does increase with improved control, the level of fun drops just before perfect control is reached (with an optimum around 96%). This poses new insights for developers of games who want to incorporate some form of BCI or other modality with unreliable input in their game: for creating a fun game, unreliable input can be used to create a challenge for the user.

Perception and Manipulation of Game Control

“…Beyond this level of control, other unknown, but control-independent, reasons seem to become dominant as the percentages become more steady. The increase in aborted runs after 1.5 bits could be related to the decrease in fun participants experienced when the level of control gets (close to) perfect -see our previous data analysis in [5].…”

“…Like other input modalities based on observations of the body, BCIs do not provide perfect recognition of what a user tries to convey [1,2,3,4]. These inputs suffer from problems related to noise, non-stationarities, and ambiguity [5]. This can be problematic, as input is the basis for usable systems in general, and recognition accuracy is most important to users of BCIs [6].…”

“…Additionally, what would be the minimum amount of control necessary to operate a given system? Previous analysis of data from this experiment has been published in [5], which posed that perfect control may not always be optimal. People actually experienced more fun in the experiment game when the control was not perfect.…”

Artistic brain-computer interfaces: state-of-the-art control mechanisms

“…Van de Laar et al [22] created an experimental game environment in order to investigate whether users' accuracies and sense of fun correlated with their sense of control. Within each round of the game, users were afforded different levels of control.…”

“…When users are in a relaxed state, their alpha waves (7-13 Hz) are transmitted and the steel sky is silent, other than one 'ding' every four seconds. When users are focused, beta rhythms (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30) are present and the steel sky lights up with cacophonous sounds of banging steel. The musical feedback prompts the user to either continue in their same mental state, or to attempt to change their current brainwave frequencies, depending on personal preference.…”