This study advances the design of timing-sensitive, full-body interactive experiences supporting both collaboration and individual agency in children’s group play. We investigate how temporal structuring within an improved version of a full-body interactive system influences behavioral and perceived synchrony among children aged 9–10. Prior research has often focused on dyads, required human facilitation, or neglected relationship between perceived and actual synchrony. Addressing these gaps, we conducted a multi-user study comparing synchronous and asynchronous interaction modes using system-logged behavioral data and self-reports. Results demonstrate the synchronous condition fosters higher user performance, tighter temporal coordination, and stronger perceptions of shared movement. In contrast, the asynchronous mode effectively disrupts unintended coordination, showing how timing design shapes interaction dynamics. Notably, identical movements are perceived as less uniform without temporal alignment. These findings highlight the potential of embodied systems to scaffold or inhibit synchrony through intentional design, supporting richer social engagement and inclusive group play.

As Mixed Reality (MR) systems evolve toward richer, full-body interactive experiences, understanding how spatial configurations shape user behavior becomes essential for designing usable, engaging, and cognitively coherent environments. This paper presents the design and evaluation of three MR mini-games developed to investigate key embodied interaction properties: (1) territoriality and social distance, (2) proprioception and kinaesthesia, and (3) navigation and wayfinding. Implemented across four differently scaled MR footprints, the games were tested with participants from three age groups, children, adolescents, and young adults, to assess how interaction space size influences bodily coordination, spatial negotiation, and social behavior. Using a multimodal analysis approach, we analyze behavioral patterns that emerge at different scales, revealing how users' interaction strategies change based on space. Our findings contribute to the human-centered design of MR systems by offering a behavioral lens on how scale influences user experience, embodiment, and interaction quality. The study informs future applications in education, social interaction, and rehabilitation, where adaptive MR design is critical for inclusive and effective engagement.

This study investigates how interpersonal synchrony (IPS) in full-body interactive Mixed Reality (MR) environments can shape children's prosocial behavior. We introduce DragonIce 2.0, a two-part MR game designed to induce synchronous or asynchronous group activity and assess their impact on prosocial behavior. To examine changes in affiliation (team belonging and peer liking) and collaboration (overt joint actions), we conducted a comparative study with children aged 9-10, using both system logs and self-report measures. The results highlight the importance of context, task structure, and perceived coordination in shaping social outcomes, offering insights into how interaction dynamics shape social engagement in immersive settings. This work contributes a novel approach for studying prosociality in ecologically valid, technology-mediated settings by combining playful, immersive interaction with controlled manipulation of group synchrony. Our findings inform the design of inclusive MR experiences that support social connection, collaboration, and group engagement among children.

A novel projective device, the AR Magic Lantern (ARML), has allowed Spatial Augmented Reality (SAR) to be deployed as a portable AR experience comparable to those on other technologies such as smartphones and headsets. In this study we compare user experience in a real virtual heritage application between two technologies that are growing in feasibility and popularity: SAR (using the ARML) and passthrough headset-AR (using the Meta Quest 3). Given that managers and curators of heritage sites want their visitors to attain a good awareness of the physical site, AR should provide a good blend between the physical and the augmented, without technology getting in the way. The results obtained seem to indicate that SAR provides higher awareness of the physical site than headset-AR. Moreover, the SAR seems to spontaneously spark experience exchange between the user and other visitors, while headset-AR tends to isolate users. Finally, headset-AR seems to put users in a task-oriented mindset while SAR seems to better contextualize the experience and its content within the physical site.

Interpersonal Synchrony (IPS), the temporal coordination of actions between individuals, plays a crucial role in fostering social interactions, emotion regulation, and communication.While previous research has explored IPS in dyadic settings, little is known about how it can be supported in multi-user full-body interactive environments, especially for neurodivergent populations.This study presents an iterative design investigation of DragonIce, a full-body interactive experience aimed at promoting IPS among children on the Autism Spectrum (AS).Building on findings from a prior study involving 12 male students with autism, we implemented and tested two targeted interaction design modifications: (1) enhanced visual feedback and (2) the introduction of a hand-held object.The results revealed a significant improvement in behavioral synchrony following refinements and a positive trend in perceived synchrony and user experience, highlighting how specific interaction design elements shape user experience and perceived synchrony in groupbased settings.This work contributes to creating knowledge on how interaction design can be strategically employed to foster IPS, offering new directions for inclusive and socially supportive full-body experiences for neurodivergent children.

This paper investigates how the physical size of a large-scale floor projected full-body interactive environment influences user behavior, focusing on territoriality and social distance across different age groups. Through an interactive game, we examined the interactions of school-age children, adolescents, and young adults in environments of varying sizes$\mathbf{3. 6} \times \mathbf{3. 6}$,$4.5 \times 4.5,5.3 \times 5.3$, and$6 \times 6$meters). Results revealed that schoolage children adapted their spatial behavior to the environment size, maintaining closer distances in smaller spaces and adjusting their play accordingly. Adolescents and young adults, however, exhibited consistent interpersonal distances across all scales, suggesting a preference for fixed personal space. These findings underscore the importance of age-related adaptability in designing interactive spaces, particularly for large-scale environments. This study provides insights into creating intuitive and effective game-based systems that support diverse user needs, offering practical guidelines for scalable, user-centered designs.

This study is part of a broader project exploring the integration of Mixed Reality (MR) in fostering prosocial behaviors among children, particularly focusing on interpersonal synchrony (IPS) and its impact on collaboration. IPS, the coordination of rhythmic movements among individuals, has been associated with improved group cohesion and prosocial behaviors, such as collaboration. Traditional assessments of prosociality typically involve structured play activities for dyads, making them difficult to adapt to other settings. To address these limitations, this research aims to design a flexible embodied MR experience that allows children to choose between collaborative or individual engagement, reflecting the natural dynamics of children's play interactions. For this purpose, we conducted an embodied participatory design (PD) and usability study with 50 children aged 8-10 years. We provide a detailed account on how the PD process was orchestrated and an evaluation of user-system interaction, children's perceptions of play modes, and experience satisfaction. The results show how the MR experience, codesigned with children, supports a free play environment, allowing children to choose their preferred play mode. This study highlights the potential of MR in psychological research and child development, providing a new avenue for assessing individual and collaborative behaviors in larger groups of children.

Embodied, co-design and children-specific methods have been gaining traction in Interaction Design for Children, and their potential and benefits are well-established. Yet methods at the intersection of all three areas are scarcer. In addition, design researchers lack tools for the analysis and adaptation of existing methods, and the creation of new ones to suit the particularities of the design project at hand. Here, we present the Think-4-EmCoDe framework for the design and analysis of embodied co-design methods and techniques for children, which foregrounds key qualities in embodied interaction design research: (1) embodied awareness; (2) reflective imaginary; (3) emergence; (4) embodied memory; (5) situated relationality; (6) contingency; (7) playful engagement; (8) play practice; (9) developmental scaffolds; and (10) social dialogue. The framework has been developed drawing from several theories, methods, and frameworks in the areas of co-design and embodied design approaches. This framework allows designers to focus on both general design qualities for embodied experiences and the specific child perspective. We illustrate the use of the framework through the analysis of three design techniques and discuss its potential as an inspirational tool to understand, adapt and refine embodied co-design techniques for children.

Research in Full-Body Interaction suggests the benefits of activities based on using embodied resources to strengthen the sensorimotor, cognitive and socio-emotional aspects of the user experience. However, scholars in this field have been often primarily concerned with the comprehension of and design for the user's mind. Little attention has been drawn on its connection to the bodily experience. The scarcity of adequate co-design methods with and for children to raise an awareness of their body during design risks of deriving interaction design decisions only from the perspective of adult designers. In this article, we present our research on novel co-design techniques to elicit children's embodied awareness. These techniques were analysed in the context of a design workshop series with a local theatre school. For the analysis, we used the Think4EmCoDe research framework, a tool to foreground key aspects of an embodied co-design technique for children. Results indicate the benefits of techniques based on physical theatre practice that (1) help children understand their body and space as mediators of ideas and meaning making processes; (2) allow them to incorporate the specific features of Full-Body Interaction in their co-design.

This study is part of a larger project that wants to foster social initiation behaviors in children with Autism Spectrum Disorder (ASD). We approach this through a full-body interactive Mixed Reality (MR) experience that mediates a face-to-face play session between an ASD child and a non-ASD child. The goal of this study is to obtain a data model that allows us to evaluate the goodness of the MR system compared to a typical social intervention strategy based on construction tools (in this case LEGO bricks) which acts as the control condition. In this paper we present our first analysis of the arousal generated by the MR experience compared to that generated in the control condition. We address this by analyzing psychophysiological data recorded during the social interaction behaviors in the ASD child while playing with the non-ASD child. We followed a repeated-measures design with two conditions: our full-body interaction MR environment and the typical social intervention strategy based on LEGO bricks. To measure physiology, Electrocardiogram (ECG), Electrodermal Activity (EDA) and Accelerometer (ACC) data were acquired through a wearable designed by our lab. We used machine learning techniques to analyze the huge amount of multimodal data from the ASD children obtained during 18 trials (3 female and 15 male). As a result, we were capable of classifying social initiation behaviors of ASD children during the MR environment sessions and those occurring during the LEGO construction sessions based on the psycho-physiological data sources. This is a first sign showing that our MR system has specific properties, compared to a traditional construction-based intervention, which potentially provide a new interesting context to intervention in ASD.

Augmented and Mixed Reality mobile technologies are becoming an emerging trend in the development of play and learning experiences for children. This tendency requires a deeper understanding of their specificities to adequately inform design. To this end, we ran a study with 36 elementary school children to compare two AR/MR interaction paradigms for mobile technologies: (1) the consolidated "Window-on-the-World" (WoW), and (2) the emerging "World-as-Support" (WaS). By analyzing children's understanding and use of space while playing an AR/MR mystery game, and analyzing the collaboration that emerges among them, we show that the two paradigms scaffold children's attention differently during the experience and elicit different forms of collaboration. We conclude by presenting a conceptual framework to distinguish the strengths, weaknesses, and potential of the two AR/MR paradigms, as well as the comparison between marker-based and marker-less technical solutions. This study aims at helping practitioners in taking design decisions for AR/MR technologies for children.

This article addresses the design and study of novel interaction settings and systems supporting collocated interaction. More specifically, we aim to analyze the implications of two different interaction approaches, namely first-person and third-person interaction paradigms, and the corresponding theoretical approaches when designing and developing collocated experiences for children with Autism Spectrum Disorders (ASDs). This analysis is supported by the outcomes of several examples of full-body interaction collocated experiences aimed at promoting social initiation and collaboration. Moreover, we present a series of goal-driven guidelines to consider when designing with various interaction paradigms. Finally, we discuss future work to better understand the implications of constructing paradigms for the intuitive use of these full-body interaction systems.

Current technical capabilities of mobile technologies are consolidating the interest in developing context-aware Augmented/Mixed Reality applications. Most of these applications are designed based on the Window-on-the-World (WoW) interaction paradigm. A significant decrease in cost of projection technology and advances in pico-sized projectors have spurred applications of Projective Augmented Reality. This research has focused mainly on technological development. However, there is still a need to fully understand its communicational and expressive potential. Hence, we define a conceptual paradigm that we call World-as-Support (WaS). We compare the WaS and WoW paradigms by contrasting their assumptions and cultural values, as well as through a study of an application aimed at supporting the collaborative improvisation of site-specific narratives by children. Our analysis of children's understanding of the physical and social environment and of their imaginative play allowed us to identify the affordances, strengths and weaknesses of these two paradigms.

Participatory Design (PD) methods have become a widespread practice in the development of digital technologies. Even if PD is grounded on a critical and reflective tradition, often the presence of implicit assumptions may have relevant methodological and ethical consequences, since they may unintentionally shape our way of considering or behaving with participants. To tackle this issue, we suggest that the assumptions and expectations of designers must be carefully examined. To guide this process, we propose using a self-reflexive critical practice based on autoethnography as a tool to reflect and construct knowledge out of our subjective experience of designers involved in PD. Grounded on our experience of PD with teenagers, we report how autoethnography allowed gaining a deeper understanding of one's own positions, assumptions and contradictions on aspects related to our standpoint on participatory practices, the images that we have of participants and our role in the design process. This awareness allowed taking into account emotions, personal stories and values in ethical choices, hence guiding situated decision-making on ethical and methodological aspects. Furthermore, we suggest that this approach not only contributes to unveil incongruences and strengthens the validity of the research, but also facilitates conditions for enabling a suitable space for creation and support novel forms of reporting PD experiences.

Autism Spectrum Disorder is characterized by impaired social communication capacities which can prevent the formation of social relationships with peers. In recent years, potential programs for people with ASD have increasingly used Information and Communication Technologies mainly motivated by the affinity that people with ASD show towards technology-supported tasks. We present the design of a full-body interaction experience called Lands of Fog, in which a child with ASD plays together with a typically developed child. The system is aimed towards fostering social interaction behaviors and collaboration. We have undertaken user trials with 34 ASD children through which Lands of Fog has proven to be a useful tool to foster social interaction. In this paper, we focus on the description of the interaction design process, methods and criteria that support the final experience. We then provide preliminary results from the user trials which provide a first hint of the efficacy of the system in fostering user's engagement and making socialization attitudes emerge.

Research based on the embodied cognition framework proposes the use of physicality and spatiality to promote learning. Nevertheless, methods to include children in the design of Full-Body Interaction Learning Environments often neglect to properly integrate the notion of body and space. In this paper, we describe a participatory design process in which we focused on how children can be encouraged to pay attention to their own body, to proxemics and to embodied constraints of the environment. We explored how this awareness may inform children's design choices for a Full-Body Interaction Learning Environment for public spaces. Our findings indicate that our approach promoted children's awareness towards bodily and spatial aspects of their proposals. Our work contributes to the reflection upon the use of bodystorming and theater-based techniques in two contexts: (1) in a simulated environment of the experience and (2) in physical spaces in situ.

We present a qualitative, idiographic study aimed at exploring how children create bridges between embodied experience and meaning construction while interacting with a Full-Body Interaction Learning Environment. Starting from the analysis of four case studies, we illustrate different possible paths through which children can transform embodied experience into an 'object--to-think-with' and delineate the different resources for meaning making that they employed. These outcomes contribute to expand the current understanding around embodied learning with interactive technologies, as well as suggest a set of qualities to think about interaction design and future research.

Despite the increasing interest in embodied interaction for learning, research has not yet provided strong proof of its advantages with respect to other types of interaction, or with respect to other types of pedagogical approaches. In this paper we present two studies aimed at comparing how a collaborative interactive experience based on two different interaction paradigms -one based on Full-Body Interaction and the other on Desktop computer interaction- may impact the socio-affective aspects of collaboration as part of a learning process in children. Our results show that Full-Body Interaction had a highly significant impact on how the participating children perceived collaboration in small groups and on how they felt about the other children in the group. This indicates that Full-Body Interaction may be beneficial for supporting the construction of a positive social space for collaborative learning, given its potential to enable the use of embodied resources, which are fundamental for social communication and social cognition.

The aim of this paper is to explore techniques to design specific gestures with children to improve the interaction design of a Full-Body Interaction Learning Environment. This exploratory case study is part of the EcoSystem Project, a learning environment aimed at supporting children's understanding of environmental issues related to air-pollution. In order to involve children in the design of the physical interaction with the system, we used two different techniques to facilitate the design of gestures: "sketching through the body" and "sketching with puppets". The results indicate that children adopted different strategies to design gestures for each technique. Within them, the most effective approach was related to the switch between performing gestures with their own bodies and simulating those gestures with puppets. This finding indicates the potential of those Participatory Design methods which combine multi-modal resources as instruments to allow children to reflect upon their own knowledge and express it more precisely.

The paper presents an exploratory study aimed toward including children in the design of an Interactive Learning Environment based on Full-Body Interaction. The study proposes a method based on using Participatory Design techniques to analyze core meanings and misconceptions of children. The aim is to identify appropriate learning goals and to define concepts capable of bridging between children's knowledge and novel contents. Furthermore, it explores a novel approach aimed at fostering design methods suitable for a Full-Body Interaction experience. The results show the benefits of the method in defining guidelines for a first design proposal of a Learning Environment based on environmental education.

In recent years there has been an increasing awareness about the importance of involving children with special needs in the process of designing technology. Starting from this perspective, the paper presents the participatory design process carried out with children with autistic spectrum disorder for the design of a Kinect motionbased game aimed at fostering social initiation skills. By describing the strategies used for the design of the activities, we will suggest possible approaches aimed toward widening the space for contributions of children and including them at a more creative level. Within that, major emphasis will be dedicated to discussing the "empowering dimension" of participatory design activities as an instrument to enhance benefits both for design results and for the children themselves. Finally, the balance between structure and freedom in the design of the activities will be discussed.

The nanoscale, despite being something "present" in our everyday life, is actually an abstract concept given the impossibility of having a direct perception of it. This article presents the design process and analysis of an interactive exhibit called "NanoZoom" for a temporary exhibition for the science museum of Barcelona. The goal of the exhibit was to help users understand how small objects are in the nanoscale by designing a fullbody interactive experience. The hypothesis behind the design of the system was based on the idea that our body is our constant referent to allow us to understand issues of scale, proportions, distances, etc. Hence, taking the body of the user as a referent should help users better understand how small objects in the nanoscale are. The approach was based on a contemporary view on the Vitruvian Man in fullbody interaction; i.e. based on modern theories that claim that embodied interaction can foster a better learning of our environment. Experimental assessment was carried out with 64 children, comparing the fullbody interactive experience with a desktop adaptation of it. Results showed better performance on children's memorability and classification of objects (ranging from the size of centimeters to the nanoscale) for those who used the fullbody experience with respect to those in the desktop system.

A rich variety of videogames promoting physical activity has followed the emergence of new full-body interfaces. Known as exergames, these active videogames are often presented in the market as a ludic substitute to traditional sport. Although they present the benefit of being engaging, to date, the content and modality of interaction of these games cannot be granted as a regular mean to do exercise. This is an issue of particular relevance when they are perceived as a valid alternative to develop children's motor skills. This paper presents the design strategies and evaluation of the "Fish Game", an exergame that has been specifically designed to spur children to execute specific types of movement determined by health experts. In a controlled assessment with 150 children, we compared the diversity of movement in the Fish Game with respect to a previously designed game. Video analysis shows a richer variety of movements was executed in the Fish Game. We discuss the limitations of our current design procedure and future avenues that could be explored with health experts to enhance it.

In Artificial Reality experiences, that is, interactive, unencumbered, full-body, 2D vision-based virtual reality (VR) experiences (heirs of the seminal Videoplace by Myron Krueger), there are two possible interaction paradigms, namely, first-person and third-person—which differ significantly from the classic VR first- and third-person notions. Up until now, these two paradigms had not been compared or objectively analyzed in such systems. Moreover, most systems are based on the third-person paradigm without a specific justification, most probably due to the influence of the original Videoplace system and because it is the only paradigm available in commercial development tools and leisure systems. For example, many rehabilitation projects have chosen to use these VR systems because of their many advantages. However, most of these projects and research have blindly adopted the third-person paradigm. Hence, the field of virtual rehabilitation has analyzed the beneficial properties of these systems without considering the first-person paradigm that could potentially present better adequacy. To find and understand potential differences between the two paradigms, we have defined an application categorization from which we developed two full-body interactive games and set up an experiment to analyze each game in both paradigms. We studied how 39 participants played these games and we quantitatively and qualitatively analyzed how each paradigm influenced the experience, the activity and the behavior of the users and the efficiency in accomplishing the required goals. We present the results of these experiments and their general implications, and especially for virtual rehabilitation due to the potential impact these systems may have in the well-being of many people.

We propose an adaptation of Participatory Design (PD) specifically conceived for full-body interaction design addressing the specificities that this entails. The idea is to include the preferences and points of view of children in the process of designing exergames allowing them to: (a) design activities that foster sufficient physical activity and a rich diversity of movement, (b) link this activity to the topic of the game and, (c) understand and test their designs at full-body scale already at prototype level.

There is a growing interest in learning studies about the use of interaction models that involve sensorimotor activities and affordances within an educational experience. This paper explores how concrete experiences, in this case an educational application designed for an Interactive Slide, can make concepts of buoyancy and Archimedes' principle understandable to children. We hypothesized that the relationship between kinesthetic experience and the Interactive Slide's affordances would improve learning. To test this hypothesis we have defined two principal experimental conditions, using the same application on the Interactive Slide and on a desktop computer, and compared the results from a sample of 331 children through pre and post-tests. Our results show modest but noticeable improvements in test scores from children assigned to the Interactive Slide condition. The results of this study highlight the opportunities of the Interactive Slide as a learning environment to foster the processes of building abstract concepts. However, additional exploration is necessary to improve the design strategies for new applications and refine the assessment methodology.

In this paper we describe a work in progress of a mixed-reality framework based on tangible interface applied to a video game designed for children. This video game, called PIPLEX, lays on the ability of the users to solve a puzzle through modelling malleable materials (namely plasticine and cardboard). We explain the implementation of PIPLEX, its interaction rules and the physical set-up. Additionally, we suggest future applications that can be developed in the context of our framework.

This paper presents a multi-user virtual heritage application that allows children to experience and learn the hunting strategies depicted in a cave painting from 6000 B.C. The application is based on a multi-touch vertical screen that allows for full-body interaction through carefully defined gestures that provide sufficient ecological naturalness and experimentation freedom to the users. This paper gives a detailed account on the experience and interaction design, agent programming and multi-touch technology.

The incipient research on interactive playgrounds is a promising field that can enhance in many ways growth, health and education of children and youngsters. In this paper, we present a novel approach to interactive playgrounds by describing the physical and interaction design of a new platform: the Interactive Slide. We concentrate on the main design issues and relate the acceptance of this platform; specifically through two applications that we have designed for it: one for children 4 to 8 years and a second for youngsters 10 to 14. This platform can provide a fertile ground for creative, leisure and educational applications and experiences. However, our main focus is on countering lack of physical activity and lack of socialization in children, which are important issues in all developed countries (and some underdeveloped ones) and especially important in Europe because of their accelerated pace of incidence.

Autism is a developmental disorder which presents disability in communication and socialisation and a lack of imagination. To promote creativity, exploration and enjoyment in low functioning autistic children that have no verbal communication, we propose MEDIATE, an interactive environment that generates real time visual, aural and vibrotactile stimuli. This paper focuses on the design of interaction with visuals within MEDIATE. The design is guided by the objectives of giving children a sense of agency and enhance non repetitive actions. Other guidelines of this design include natural interaction, use of non invasive technology and non representational visuals. This visual interaction (together with sound and vibrotacile) allows the children to enjoy MEDIATE and be creative within this environment.

This paper presents an adaptive physical environment that allows children with severe autism to successfully interact with multimodal stimuli, giving them a sense of control of the interaction and, hence, providing them with a sense of agency. This has been an extremely important effort for two main reasons: 1) This user group cannot be typified, hence making the design of an interactive system to fit all the spectrum of individuals a very complex task; 2) each individual PAS (Person on the Autistic Spectrum) user must be able to develop himself within the environment according to his own capacities and potentiality. Qualitative evaluation by psychologists shows very good results and sketches an encouraging future for research on these environments.