Alejandro Catala

The European Union’s regulatory ecosystem presents challenges balancing legal and sociotechnical drivers for explainable AI systems. Core tensions emerge on dimensions of oversight, user needs and litigation. This paper maps provisions on algorithmic transparency and explainability across major EU data, AI, and platform policies using qualitative a...

Life Story books are frequently employed to facilitate reminiscence interventions, but their use in music therapy remains limited in the scientific literature. There is a paucity of research detailing the design processes involved in this context. In contemporary music therapy, the effective integration of technology is a significant AQ1 concern. T...

INTRODUCTION: Life Story books are frequently employed to facilitate reminiscence interventions, but their use in Music Therapy remains limited in the scientific literature. There is a paucity of research detailing the design processes involved in this context. OBJECTIVES: This paper aims to report on the adaptation of the Emobook Life Story Book A...

Fuzzy systems are known to provide not only accurate but also interpretable predictions. However, their explainability may be undermined if non-semantically grounded linguistic terms are used. Additional non-trivial challenges would arise if a prediction were to be explained counterfactually, i.e., in terms of hypothetical, non-predicted outputs. I...

Explainable artificial intelligence has become a vitally important research field aiming, among other tasks, to justify predictions made by intelligent classifiers automatically learned from data. Importantly, efficiency of automated explanations may be undermined if the end user does not have sufficient domain knowledge or lacks information about...

The successful irruption of AI-based technology in our daily lives has led to a growing educational, social, and political interest in training citizens in AI. Education systems now need to train students at the K-12 level to live in a society where they must interact with AI. Thus, AI literacy is a pedagogical and cognitive challenge at the K-12 l...

The explanatory capacity of interpretable fuzzy rule-based classifiers is usually limited to offering explanations for the predicted class only. A lack of potentially useful explanations for non-predicted alternatives can be overcome by designing methods for the so-called counterfactual reasoning. Nevertheless, state-of-the-art methods for counterf...

Promoting the social-emotional development of kindergartners is of special relevance as will lay the foundations for emotion regulation in later childhood and adulthood stages. Considering that tangible storytelling tables are already used for language and literacy skills in kindergarten, we addressed the problem of designing a storytelling interve...

Smart toys are regarded as able to offer possibilities to develop social, cognitive, and behavioural skills (among others); however, while appealing, such claims are not yet substantiated by rigorous and sufficient scientific evidence. The first edition of the workshop on Smart Toys, Smart Tangibles, Robots and other Smart Things for Children took...

In this chapter, a Negative User Experience (NUX)-based method for deriving sustainability requirements of persuasive software systems is proposed. The method relies on the analysis of NUX assessment, and the exploitation of relationships between the SQ model and the PSD model, which are well-known models for sustainability-quality in software syst...

A number of algorithms in the field of artificial intelligence offer poorly interpretable decisions. To disclose the reasoning behind such algorithms, their output can be explained by means of so-called evidence-based (or factual) explanations. Alternatively, contrastive and counterfactual explanations justify why the output of the algorithms is no...

In this chapter, we describe how to generate not only interpretable but also self-explaining fuzzy systems. Such systems are expected to manage information granules naturally as humans do. We take as starting point the Fuzzy Unordered Rule Induction Algorithm (FURIA for short) which produces a good interpretability-accuracy trade-off. FURIA rules h...

Data-driven classification algorithms have proven highly effective in a range of complex tasks. However, their output is sometimes questioned, as the reasoning behind it may remain unclear due to a high number of poorly interpretable parameters used when training. Evidence-based (factual) explanations for single classifications answer the question...

Smart and robotic toys introduce more possibilities than ever for building interactive settings for playful learning. Here we explore their use for supporting the development of storytelling skills in children. Previous research on interactive storytelling prototypes has already shown their potential to this end. However, the focus has often been s...

Ensuring the quality of user experience is very important for increasing the acceptance likelihood of software applications, which can be affected by several contextual factors that continuously change over time (e.g., emotional state of end-user). Due to these changes in the context, software continually needs to adapt for delivering software serv...

[Background] A software sustainability model is commonly defined in terms of social, economic, technical and environmental dimensions. A key challenge is its characterization regarding sustainability requirements and their dependencies since it depends on, and varies with, the type of software system, and changes in operational contexts. [Aims] Wit...

Both storytelling and learning by teaching approaches have shown to be beneficial separately when integrating robots into learning settings. This paper discusses how to combine them, based on principles found in the literature, and presents the design and implementation of a playful robot application for second language (L2) learning targeted at pr...

In recent years, several stress detection methods have been proposed, usually based on machine learning techniques relying on obstructive sensors, which could be uncomfortable or not suitable in many daily situations. Although studies on emotions are emerging and rising in Software Engineering (SE) research, stress has not been yet well investigate...

In recent years, several stress detection methods have been proposed, usually based on machine learning techniques relying on obstructive sensors, which could be uncomfortable or not suitable in many daily situations. Although studies on emotions are emerging and rising in Software Engineering (SE) research, stress has not been yet well investigate...

The design of Tangible User Interfaces (TUIs) has often involved children. Nowadays, the term co-creation is gaining momentum and extending the already established role of children as co-designers. In this sense children become creators of new personalized experiences not only during the design process but also when using the final interactive prod...

Behavior Change Software systems (BCSSs) have shown promising outcomes in terms of promoting healthy behaviors. However, a negative User Experience (UX) can be induced by BCSS if designers do not have clear understanding of the requirements that factually help in changing the user behavior that achieves a sustainability goal. In order to get insigh...

This paper explores the use of a remotely controlled character to be used by children in storytelling activities. The character is implemented in a moveable tablet or surfacebot, which supports the development of inexpensive expressive agents capable of moving around in real space, applicable in diverse play contexts. We carried out an exploratory...

This workshop aims to explore challenges and potential opportunities in bringing interactive digital storytelling into the realm of tangible and embodied interaction. To this end, experts from both fields are invited to present and discuss their ideas. Besides fostering discussion and potential collaborations, the goal is to come up with new and su...

There is growing interest in the automatic detection of animals’ behaviors and body postures within the field of Animal Computer Interaction, and the benefits this could bring to animal welfare, enabling remote communication, welfare assessment, detection of behavioral patterns, interactive and adaptive systems, etc. Most of the works on animals’ b...

In our ongoing research, we argue that storytelling activities can be used as creative tasks to stimulate creativity in children, one of the so-called 21st century skills. In this paper, we lay the foundations for our project on digitally supported storytelling, by gathering the viewpoints on storytelling and creativity expressed by local primary s...

Touch displays moving autonomously, i.e., being self-actuated, are starting to be part of system prototypes reported in the literature. In the future, user interactions with such prototypes may take place while the display is moving. However, since current prototypes do not yet require this type of interaction, there is a lack of empirical evidence...

User-centered design applied to non-human animals is showing to be a promising research line known as Animal Computer Interaction (ACI), aimed at improving animals' wellbeing using technology. Within this research line, intelligent systems for animal entertainment could have remarkable benefits for their mental and physical wellbeing, while providi...

In most haptic search tasks, tactile stimuli are usually presented to the fingers to discriminate simulated features and identify patterns. In this paper, we focus on a more complex exploration task in which users have to discriminate different stimuli, move their fingers in a free way to find and locate an object in a wider area of exploration and...

This paper evaluates MarkAirs, an interaction technique that uses fiducial markers to perform mid-air interactions. MarkAirs offers several advantages: the proposed technique does not require any tracking external hardware other than the front camera of a mobile device; it is robust even when the markers are partially occluded; and it enables preci...

The direct manipulation interaction style of multitouch technology makes it an ideal mechanism for implementing learning activities for prekindergarten children. This is feasible because recent studies have shown that users in this early age range are able to perform a complete set of basic multitouch gestures. However, it is still unknown whether...

Entertainment technology increases children’s engagement in educational activities designed to develop abilities rang-ing from collaborative problem-solving and cognitive atten-tion to self-esteem. However, little research has been done on designing educational and entertaining interactive tech-nology for kindergarten children (up to 5 years old)....

Digital games for animals within Animal Computer Interaction are usually single-device oriented, however richer interactions could be delivered by considering multimodal environments and expanding the number of technological elements involved. In these playful ecosystems, animals could be either alone or accompanied by human beings, but in both cas...

This paper presents Airsteroids, a multi-player re-design of the classic arcade game Asteroids. The re-design makes use of handheld devices such as tablets and Smartphones and of MarkAirs, an around-device interaction (ADI) with fiducial markers that reduces occlusion on the screens and interference between users’ interactions.

Digital tabletops present numerous benefits in face-to-face collaboration envi-ronments. However, their integration in real settings is complicated by cost and fixed location. In this respect, building table-like environments using several handheld devices such as tablets or smartphones provides a promising alternative but limited to touch interact...

Long-term and frequent hospitalized children are under high loads of emotional stress, which affects their well-being in addition to the illness they are suffering. This thesis proposes and will focus on an approach to use Multi-Display Environments (MDE) in pediatric hospitalization contexts to improve patients' emotional intelligence so they can...

We are evolving towards an interconnected and ubiquitous world, where digital devices and interfaces progressively adapt themselves to fit our needs and ease our daily activities. Although we coexist with plenty of animal species, such as our pets, we are approaching the evolution of technology in a strictly human-centric manner. A new field in Com...

Smart environments are becoming a reality in our society and the number of intelligent devices integrated in these spaces is increasing very rapidly. As the combination of intelligent elements will open a wide range of new opportunities to make our lives easier, final users should be provided with a simplified method of handling complex intelligent...

The creation of artefacts and entities to be used in simulated worlds and games has been used in practice to foster creativity in informal activities. Motivational issues and entertainment have therefore been combined along with creative tasks. The systems with higher complexity and more creative capabilities are usually based on WIMP interfaces, w...

The continuous and rapidly increasing elderly population requires a revision of technology design in order to devise systems usable and meaningful for this social group. Most applications for ageing people are built to provide supporting services, taking into account the physical and cognitive abilities that decrease over time. However, this paper...

Play stands as one of the most natural and inherent behavior among the majority of living species, specifically humans and animals. Human play has evolved significantly over the years, and so have done the artifacts which allow us to play: from children playing tag games without any tools other than their bodies, to modern video games using haptic...

The advent of wearables (e.g., smartwatches, smartglasses, and digital jewelry) anticipates the need for text entry methods on very small devices. We conduct fundamental research on this topic using 3 qwerty-based soft keyboards for 3 different screen sizes, motivated by the extensive training that users have with qwerty keyboards. In addition to Z...

The direct manipulation interaction style of multi-touch technology makes it the ideal mechanism for learning activities from pre-kindergarteners to adolescents. However, most commercial pre-kindergarten applications only support tap and drag operations. This paper investigates pre-kindergarteners’ (2-3 years of age) ability to perform other gestur...

Pre-kindergarten children are becoming frequent users of multi-touch technology and, according to previous studies they are able to perform several multi-touch gestures successfully. However, they do not use these devices supervised at all times. Consequently, interactive applications for pre-kindergarteners need to convey their underlying design i...

Multi-touch technology provides users with a more intuitive way of interaction. However, pre-kindergarten children, a growing group of potential users, have problems with some basic gestures according to previous studies. This is particularly the case of the double tap and long pressed gestures, which have some issues related to spurious entry even...

When looking for effective ways to understand how animals interact with computer-mediated systems, ACI studies should rely on their most natural and intrinsic behavior: play. Animals were playing before humans could teach them how to do it. Playful environments are thus a promising scenario in which to start developing systems which have animals as...

Previous work in the literature has shown that back-of-device (BoD) authentication is significantly more secure than standard front-facing approaches. However, the only BoD method available to date (Bod Shapes) is difficult to perform, especially with one hand. In this paper we propose Bod Taps, a novel approach that simplifies BoD authentication w...

This demonstration accompanies a paper accepted at MobileHCI'14. Back-of-device (BoD) authentication has shown to be significantly more secure than standard front-facing approaches, being BoD Shapes the most representative method found in the literature. With the aim of getting a better understanding and improving its usage, we developed BoD Taps a...

Digital media and software have been used in supporting learning. Activities based on games should place the emphasis on the phase of creating artifacts for the game world, not on just playing or consuming contents. This chapter briefly reviews a number of outstanding efforts on providing advanced systems for the creation of digital games or simula...

La reunión de varios usuarios alrededor de una mesa para realizar actividades de juego colaborativas ha demostrado ser beneficiosa en términos de productividad, calidad de los resultados y fomento del aprendizaje entre otros. Sin embargo, el alto coste de las superficies interactivas tradicionales ha limitado su implantación de forma generalizada....

Creativity is of vital importance for human development since it allows individuals and ultimately society to successfully overcome new challenges. Besides social factors, the environment can also influence the development of such an important skill. We therefore considered it of interest to explore this capacity in the context of the new informati...

Differentiating between users that interact on a tabletop could be beneficial for collaborative tasks to support territoriality-oriented features such as a more efficient space management or a better presentation of the contents. In this paper, we design a novel algorithm for the user differentiation or segmentation based on the simultaneous manipu...

A considerable part of the behavior in smart environments relies on event-driven and rule specification. Rules are the mechanism most often used to enable user customization of the environment. However, the expressiveness of the rules available to users in editing and other tools is usually either limited or the available rule editing interfaces ar...

This paper revisits the idea of involving creativity along entertainment. The review of the related work shows that the creation of artifacts is usually directed to programming simulations and the creation of entities to be involved during the play. It is observed that proposals providing more creative capabilities are usually based on WIMP interfa...

In this paper we present our research to extend a recommender system based on a semantic multicriteria ant colony algorithm to allow the use of Allen temporal operators. The system utilizes user's learnt routes, including their associated context information, in order to predict the most likely route a user is following, given his current location...

Interactive tabletops are considered as useful tools to enrich activities requiring collaboration between co-located users involved in tasks in which organizational or spatial information is meaningful. Creative learning could also benefit from tabletop technologies because their interaction specific characteristics could better support or improve...

Children nowadays consume and manage lots of interactive digital software. This makes it more interesting and powerful to use digital technologies and videogames supporting learning experiences. However, in general, current digital proposals lack of in-situ social interaction supporting natural exchange and discussion of ideas in the course of crea...

Modern technology has brought many changes to our everyday lives. Our need to be in constant touch with others has been met with the cellphone, which has become our companion and the convergence point of many technological advances. The combination of capabilities such as browsing the Internet and GPS reception has multiplied the services and appli...

In this paper we present TangiWheel, a collection manipulation widget for tabletop displays. Our implementation is flexible, allowing either multi-touch or interaction, or even a hybrid scheme to better suit user choice and convenience. Different TangiWheel aspects and features are compared with other existing widgets for collection manipulation. T...

Creativity is a relevant characteristic for people's development as it facilitates the generation of new ideas and innovation processes. Although technology has played an important role on creativity stimulation, it still needs to be explored for a better understanding and support in the context of information and communication technologies. In thi...

In this paper we address the problem of music playlist generation based on the user-personalized specification of context information. We propose a generic semantic multicriteria ant colony algorithm capable of dealing with domain-specific problems by the use of ontologies. It also employs any associated metadata defined in the search space to feed...

Information technology has supported learning in many different ways as improvements in communication, virtual environment embodiment and even mobility has allowed remote discussion and collaboration in exploring topics and developing ideas. However, learning environments often lack validation studies related to the grounding technology being used...

Information technology has supported learning in many different ways as improvements in communication, virtual environment embodiment and even mobility has allowed remote discussion and collaboration in exploring topics and developing ideas. However, learning environments often lack validation studies related to the grounding technology being used...

Pese a que los entornos y lenguajes específicamente diseñados para programadores noveles deberían ser de utilidad, programar todavía resulta complicado para adolescentes no expertos. Más aún si se trata de juegos reactivos basados en reglas, en los que el usuario marca el hilo de la historia. Para este tipo de entornos en los que escribir código pa...

Resumen. Las superficies horizontales se han mostrado idóneas para aplicaciones interactivas de tiempo real, en las que la salida del sistema puede determinarse directamente en función de los tangibles e interacciones que ocurren sobre la superficie en cada instante. Sin embargo, no se ha explorado en profundidad su uso para soportar aplicaciones o...

Departing from creative learning foundations, this paper discusses on the suitability of interactive tables as a grounding technology to support creative learning for several reasons: support for social learning, because the subjects share a physical space as in traditional non-digital technologies, communication during the creative, experimental a...

Resumen. Partiendo de los fundamentos del aprendizaje creativo, se ha desarrollado un entorno de edición y simulación de estructuras físicas sobre superficies interactivas. Este entorno se presenta como tecnología base para dar soporte al aprendizaje creativo por varias razones: el apoyo al aprendizaje social, puesto que los sujetos comparten un es...

In this paper we address the problem of personalization and automatic generation of museum visits with mobile devices guidance. We propose here a ubiquitous software and hardware infrastructure that supports, in a collaborative way, the generation of museum handheld-based visits. Particularly, we define the problem to be solved as an instance of th...

Pathfinding is one of the tasks, apart from graphics rendering, requiring most CPU resources. Although there are many approaches to effectively solve pathfinding problems, they are becoming less suitable as more and more games have larger game worlds that dynamically change during the game play. These new games have more visually realistic graphics...

Commercial games for learning purposes have been widely used with relative success. However, very often game content hardly fits to the curriculum content, players lack direct communication, and the focus is only on learning by playing. In this paper we argue that a more interesting approach for learning is to involve players in the design process...

As ubiquitous virtual reality (U-VR) systems become more and more popular and several systems coexist all together, sharing events between them in order to improve the user experience and increase their scope and functionality will be mandatory. Since U-VR systems have a dynamic and decoupled nature, and they have their own event model, we propose...

Learning is a never ending activity for humans; it takes place everywhere and even when we do not realize. However, current learning environments make students deal with lectures, mostly associated with low control of the situation and implicit motivation. In contrast, previous researches have shown that sports, games or hobbies are activities that...

Ant colony optimization (ACO) is being used to solve many combinatorial problems. However, existing implementations fail to solve large instances of problems effectively. In this paper we propose two ACO implementations that use graphical processing units to support the needed computation. We also provide experimental results by solving several ins...