Abstract When two people (or a person and a dialogue system) interact verbally, they build and then reuse mutual knowledge, or common ground. The goal of this work was to determine whether such common ground established with a system is device-specific or whether it can be transferred across devices. To answer this question, we used an adapted version of the matching task in which a participant had the opportunity to describe abstract pictures (Tangrams) to a Wizard of Oz system, thus creating common ground regarding how to refer to these pictures with the system. The participant then performed the same task again, but using a different device. The results suggested that the participants reused the common ground used with the first device when interacting with the second device, suggesting that this knowledge was perceived as shared with the system and as transferrable across devices. Theoretical implications as well as applications for the design of multidevice systems are discussed.

This study explores the acceptability of a humanoid robot in the homes of deaf children with cochlear implants. Traditional audiologic rehabilitation, usually conducted at hospitals or clinics, significantly improves communication but geographical distance and parental availability pose challenges for families. Introducing home training with a humanoid robot could provide greater equity in care distribution, aid in the child’s progress, and offer an ecological approach. Here, ten families (11 cochlear-implanted (CI) children aged 7–12 years and their parents) participated in a study evaluating the acceptability of the humanoid robot (called Pepper) in their homes for one month. We identified two distinct clusters among the 11 CI children. The first cluster ("younger CI Children") demonstrated better and higher scores for acceptability, usability, usefulness, emotion, and fun, and used the robot more than children in the second cluster ("older CI children"). We found a decrease in both duration of use and number of applications launched by CI children each week when interacting with the robot. Parents showed similar results to their children, with parents of younger CI children demonstrating greater acceptance of the robot. Various technical issues (transcription errors, robot non-responsiveness, and comprehension difficulties) may have affected the robot’s acceptability among both CI children and their parents. Both CI children and parents expected humanoid robots to have more advanced capabilities, including high social intelligence, advanced artificial intelligence, voice assistant features, and Natural Language Processing integration.

Enjoyment is a widely assessed dimension of the video game player’s experience. A systematic literature review and a meta-analysis were conducted to provide a more comprehensive view of the elements of game design that affect the feeling of enjoyment, as well as its assessment techniques. The review showed that the studies covered major aspects of game design, such as in-game contents, input/output information, and, to a lesser extent, multiplayer aspects. The meta-analysis showed that only the presence of music in the game had a significant effect on enjoyment. Other factors, including more studied factors such as game difficulty and control mode, did not show significant effects. Implications for future research are discussed, such as further investigation of the effects of both player and game characteristics diversity on enjoyment in isolation and in interaction with game design factors, systematic use of standardized scales to measure enjoyment, and use of multidimensional scales or physiological measures.

Abstract Flow is a mental state of intense concentration that occurs when a person is completely absorbed in a task. The amount of mental effort required by this mental state is currently subject to debate. The present experimental study explored the link between flow and both objective and subjective measures of mental effort. Subjective measures of flow and mental effort, and objective measures of mental effort (pupil diameter and heart rate variability), were collected during a puzzle video game played at one of three levels of difficulty: too easy, optimal and too difficult. Participants in the optimal condition reported more flow than those in both the too-easy condition (which generated less mental effort and less subjective mental effort) and too-difficult condition (which generated an equal amount of mental effort and more subjective mental effort). Flow is a state that may require mental effort, even if it feels effortless for video game players.

This study aimed to investigate how different characteristics of head-up displays (HUDs) can impact the performance and subjective experience of players in action video games. HUDs are a very common way to display contextual information. However, very few studies have empirically investigated the influence of HUD design on player performance and experience from a human information processing perspective. Four experiments were conducted in which players of different levels of expertise played commercial action video games. The physical characteristics of HUD, that is, the physical appearance of the information on screen, such as size and colour (Experiments 1–2), and the semantic characteristics, that is, the composition (nature and content) of the information (Experiments 3–4), were manipulated. Player performance and subjective experience were systematically assessed. The results showed that players’ performance and experience were impacted when the semantic characteristics of the HUD elements were manipulated and when their nature was relevant to the main task players have to perform within the game. The performance of more experienced players was particularly affected in this case. In contrast, the results did not show that altering physical or semantic characteristics that were less relevant to the game’s main task would affect players’ performance and subjective experience.

Navigation of robots among humans is still an open problem, especially in confined locations (e.g. narrow corridors, doors). This article aims at finding how an anthropomorphic robot, like a PR2 robot with a height of 1.33 m, should behave when crossing a human in a narrow corridor in order to increase its usability. Two experiments studied how a combination of robot head behavior and navigation strategy can enhance robot legibility. Experiment 1 aimed to measure where a pedestrian looks when crossing another pedestrian, comparing the nature of the pedestrian: human or a robot. Based on the results of this experiment and the literature, we then designed a robot behavior exhibiting mutual manifestness by both modifying its trajectory to be more legible, and using its head to glance at the human. Experiment 2 evaluated this behavior in real situations of pedestrians crossing a robot. The visual behavior and user experience of pedestrians were assessed. The first experiment revealed that humans primarily look at the robot's head just before crossing. The second experiment showed that when crossing a human in a narrow corridor, both modifying the robot trajectory and glancing at the human is necessary to significantly increase the usability of the robot. We suggest using mutual manifestness is crucial for an anthropomorphic robot when crossing a human in a corridor. It should be conveyed both by altering the trajectory and by showing the robot awareness of the human presence through the robot head motion. Small changes in robot trajectory and manifesting robot perception of the human via a user identified robot head can avoid users' hesitation and feeling of threat.

When playing action video games, an optimal experience implies the presence of a head-up display that informs players on their status in regard of their goal like health points or their localization in the environment. However, how can this type of information can be integrated in new gaming contexts like virtual reality? Should this information be integrated into the game universe (diegetic design) or stay out of it (non-diegetic design)? For this purpose, the performance, presence, and enjoyment of 41 players have been measured during a virtual reality first-person shooter game session with a diegetic and a non-diegetic interface. The results showed that diegetic integration has a positive effect on the player’s performance but not on the subjective experience (presence and enjoyment). The study also shed light on the moderator role of expertise in action games on this effect because the diegetic interface only benefited novice players.

This paper presents an approach to verifying the activities of daily living of older adults at their home. We verify activities, instead of inferring them, because our monitoring approach is driven by routines, initially sketched by users in their environment. Monitoring is supported by a lightweight sensor infrastructure, comprising non-intrusive, low-cost, wireless devices. Verification is performed by applying a simple formula to sensor log data, for each activity of interest. The result value determines whether an activity has been performed.

This study examined the effects of the number of options in a message and different message endings on the memorisation of multiple-option messages. Twenty-seven participants were told to pay attention to the quality of interactions between users and an interactive voice response system and were asked to recall system messages. The multiple-option messages contained three, five or seven options and ended either in a pseudoword suffix, in a natural-language prompt or in a beep. Results showed that option recall was impaired when messages were longer and contained a suffix. The interaction between the number of options and the presence of a suffix was not significant. Results also showed that, in messages with five or more options, the recency effect was greater than the primacy effect. These results bolster our knowledge about the design of spoken menus.