Measuring Presence in Virtual Environments: A Survey

The effectiveness of a virtual reality experience is strongly affected by the sense of presence of the users involved. This article reviews the different definitions of presence and the main proposed methods to measure it through the analysis of 1,214 papers published in the past 30 years. From the analysis of 239 user studies, we found that 85.8% used subjective measures, 11.7% used a combination of subjective and objective measures, while 2.5% used only objective measures. We also identified, from the studies reviewed, 29 main factors to evoke presence in virtual environments, grouped into four categories: Engagement, Personal Characteristics, Interaction Fidelity, and Display Fidelity.

An explainable assistant for multiuser privacy

Multiuser Privacy (MP) concerns the protection of personal information in situations where such information is co-owned by multiple users. MP is particularly problematic in collaborative platforms such as online social networks (OSN). In fact, too often OSN users experience privacy violations due to conflicts generated by other users sharing content that involves them without their permission. Previous studies show that in most cases MP conflicts could be avoided, and are mainly due to the difficulty for the uploader to select appropriate sharing policies. For this reason, we present ELVIRA, the first fully explainable personal assistant that collaborates with other ELVIRA agents to identify the optimal sharing policy for a collectively owned content. An extensive evaluation of this agent through software simulations and two user studies suggests that ELVIRA, thanks to its properties of being role-agnostic, adaptive, explainable and both utility- and value-driven, would be more successful at supporting MP than other approaches presented in the literature in terms of (i) trade-off between generated utility and promotion of moral values, and (ii) users’ satisfaction of the explained recommended output.

Triggermuscle: Exploring Weight Perception for Virtual Reality Through Adaptive Trigger Resistance in a Haptic VR Controller

It is challenging to provide users with a haptic weight sensation of virtual objects in VR since current consumer VR controllers and software-based approaches such as pseudo-haptics cannot render appropriate haptic stimuli. To overcome these limitations, we developed a haptic VR controller named Triggermuscle that adjusts its trigger resistance according to the weight of a virtual object. Therefore, users need to adapt their index finger force to grab objects of different virtual weights. Dynamic and continuous adjustment is enabled by a spring mechanism inside the casing of an HTC Vive controller. In two user studies, we explored the effect on weight perception and found large differences between participants for sensing change in trigger resistance and thus for discriminating virtual weights. The variations were easily distinguished and associated with weight by some participants while others did not notice them at all. We discuss possible limitations, confounding factors, how to overcome them in future research and the pros and cons of this novel technology.

Effect of Adaptive Guidance and Visualization Literacy on Gaze Attentive Behaviors and Sequential Patterns on Magazine-Style Narrative Visualizations

We study the effectiveness of adaptive interventions at helping users process textual documents with embedded visualizations, a form of multimodal documents known as Magazine-Style Narrative Visualizations (MSNVs). The interventions are meant to dynamically highlight in the visualization the datapoints that are described in the textual sentence currently being read by the user, as captured by eye-tracking. These interventions were previously evaluated in two user studies that involved 98 participants reading excerpts of real-world MSNVs during a 1-hour session. Participants’ outcomes included their subjective feedback about the guidance, and well as their reading time and score on a set of comprehension questions. Results showed that the interventions can increase comprehension of the MSNV excerpts for users with lower levels of a cognitive skill known as visualization literacy. In this article, we aim to further investigate this result by leveraging eye-tracking to analyze in depth how the participants processed the interventions depending on their levels of visualization literacy. We first analyzed summative gaze metrics that capture how users process and integrate the key components of the narrative visualizations. Second, we mined the salient patterns in the users’ scanpaths to contextualize how users sequentially process these components. Results indicate that the interventions succeed in guiding attention to salient components of the narrative visualizations, especially by generating more transitions between key components of the visualization (i.e., datapoints, labels, and legend), as well as between the two modalities (text and visualization). We also show that the interventions help users with lower levels of visualization literacy to better map datapoints to the legend, which likely contributed to their improved comprehension of the documents. These findings shed light on how adaptive interventions help users with different levels of visualization literacy, informing the design of personalized narrative visualizations.

APONTAMENTOS SOBRE POTENCIAIS RELAÇÕES ENTRE DESINFORMAÇÃO, COMPORTAMENTO E PRÁTICAS INFORMACIONAIS

Ensaio que discute relações estabelecidas e potencialidades entre os conceitos de pós-verdade e desinformação no âmbito dos estudos de comportamentos e práticas informacionais que se efetivam na web, tendo como referência o paradigma social da Ciência da Informação. Assim, com o propósito de facilitar a compreensão e contribuir em relação à suplementaridade e convergência desses conceitos quanto abordagens de estudos de usuários, neste ensaio elencamos as distinções dos desdobramentos conceituais do termo desinformação e os tensionamentos potencializadores de estudos futuros. As reflexões permitem afirmar que a desinformação se consagra como cerne para a compreensão dos fenômenos informacionais no contexto do capitalismo cognitivo, através de comportamentos e práticas informacionais que instrumentalizam e deturpam os processos de comunicação até então consolidados.AbstractThis essay discusses established relations and potentialities between the concepts of post-truth and misinformation in the context of studies of informational behaviors and practices that take place on the web, having as reference the social paradigm of Information Science. Thus, with the purpose of facilitating the understanding and contributing in relation to the supplementarity and convergence of these concepts as approaches to user studies, we list the distinctions of the conceptual unfoldings of the term misinformation and the potential tensioning of future studies. The reflections allow us to affirm that misinformation is consecrated as the core for the understanding of informational phenomena in the context of cognitive capitalism, through informational behaviors and practices that instrumentalize and distort the communication processes consolidated until then.

SpeeChin

This paper presents SpeeChin, a smart necklace that can recognize 54 English and 44 Chinese silent speech commands. A customized infrared (IR) imaging system is mounted on a necklace to capture images of the neck and face from under the chin. These images are first pre-processed and then deep learned by an end-to-end deep convolutional-recurrent-neural-network (CRNN) model to infer different silent speech commands. A user study with 20 participants (10 participants for each language) showed that SpeeChin could recognize 54 English and 44 Chinese silent speech commands with average cross-session accuracies of 90.5% and 91.6%, respectively. To further investigate the potential of SpeeChin in recognizing other silent speech commands, we conducted another study with 10 participants distinguishing between 72 one-syllable nonwords. Based on the results from the user studies, we further discuss the challenges and opportunities of deploying SpeeChin in real-world applications.

Map Evaluation under COVID-19 restrictions: A new visual approach based on think aloud interviews

With the beginning of the COVID-19 pandemic, the execution of eye-tracking user studies in indoor environments was no longer possible, and remote and contactless substitutes are needed. With this paper, we want to introduce an alternative method to eye tracking, completely feasible under COVID-19 restrictions. Our main technique are think aloud interviews, where participants constantly verbalize their thoughts as they move through a test. We record the screen and the mouse movements during the interviews, and analyse both the statements and the mouse positions afterwards. With this information, we can encode the approximate map position of the user’s attention for each second of the interview. This allows us to use the same visual methods as for eye-tracking studies, like attention maps or trajectory maps. We implement our method conducting a user study with 21 participants to identify user behaviour while solving high-level interpretation tasks, and with the results of this study, we can show that or new method provides a useful substitute for eye-tracking user studies.

Verbal Aggression on Social Media: How, why and its Automatic Identification

In recent times, verbal aggression and related phenomena of hate speech, abusive language, trolling, etc. have become a major problem over social media. In this paper, I present the results of a large-scale quantitative study of aggression based on a target-based typology in a manually-annotated multilingual dataset of over 20,000 Facebook comments and tweets each written in Hindi, English or code-mixed Hindi-English. Taking insights from this study, I develop 2 different classifiers for detecting aggression in Hindi, English and Hindi-English mixed Facebook and Twitter conversations. The classifiers are developed using an annotatedcorpus of approximately 9,000 Facebook comments and 5,000 tweets. Since a phenomenon like aggression is highly subjective, the study shows a comparatively modest inter-annotator agreement of 0.72 and an overall F1 score of 0.64 for both Facebook and Twitter. Consequently, I also carried out two user studies, where humans were asked to evaluate the annotations by the classifier, to test the actual 'acceptance' of the classifier's judgments. I discuss the results of this user study and give an analysis of the overall performance of the system.

Exploring Behavioral Creativity of a Proactive Robot

Creativity, in one sense, can be seen as an effort or action to bring novelty. Following this, we explore how a robot can be creative by bringing novelty in a human–robot interaction (HRI) scenario. Studies suggest that proactivity is closely linked with creativity. Proactivity can be defined as acting or interacting by anticipating future needs or actions. This study aims to explore the effect of proactive behavior and the relation of such behaviors to the two aspects of creativity: 1) the perceived creativity observed by the user in the robot’s proactive behavior and 2) creativity of the user by assessing how creativity in HRI can be shaped or influenced by proactivity. We do so by conducting an experimental study, where the robot tries to support the user on the completion of the task regardless of the end result being novel or not and does so by exhibiting anticipatory proactive behaviors. In our study, the robot instantiates a set of verbal communications as proactive robot behavior. To our knowledge, the study is among the first to establish and investigate the relationship between creativity and proactivity in the HRI context, based on user studies. The initial results have indicated a relationship between observed proactivity, creativity, and task achievement. It also provides valuable pointers for further investigation in this domain.