Luís Carriço

University of Lisbon | UL · Faculty of Science

Introduction Computer confidence and computer self-efficacy can impact an individual's perceived ease of use and usefulness of technology, ultimately determining adherence to digital healthcare services. However, few studies focus on assessing the impact of non-clinical factors on the efficacy and adherence to digital healthcare platforms. Objecti...

When users leave their mobile devices unattended, or let others use them momentarily, they are susceptible to privacy breaches. Existing technological defenses, such as unlock authentication or account switching, have proven to be unpopular. We conducted interviews to uncover practices users currently engage in to cope with the threat, and found th...

Background: Mild cognitive impairment (MCI) and dementia are associated with increased age. MCI is a clinical entity described as a transitional state between normal cognition and dementia. Video games (VGs) can potentially promote cognition and functional capacity since multiple cognitive domains are recruited during gameplay. However, there is s...

Virtual environments for therapy are scarce and lack personalization. The creation of these environments is done by specialists, is time-consuming, and expensive. We present a smartphone tool that allows non-specialists to create navigable virtual environments by taking and linking sequences of panoramic photo spheres, analogly to Google Street Vie...

Mild cognitive impairment (MCI) is characterized by cognitive, psychological, and functional impairments. Digital interventions typically focus on cognitive deficits, neglecting the difficulties that patients experience in instrumental activities of daily living (IADL). The global conjecture created by COVID-19 has highlighted the seminal importanc...

Users are susceptible to privacy breaches when people close to them gain physical access to their phones. We present logging as a security response to this threat, one that is able to accommodate for the particularities of social relationships. To this end, and explore the feasibility of the logging approach, we present a prototype developed for An...

Game-based interventions (GBI) have been used to promote health-related outcomes, including cognitive functions. Criteria for game-elements (GE) selection are insufficiently characterized in terms of their adequacy to patients' clinical conditions or targeted cognitive outcomes. This study aimed to identify GE applied in GBI for cognitive assessmen...

Mobile devices are the tools of the trade to access services and contents on the Internet, already surpassing their desktop counterparts. These gadgets are always available and provide access to social networks, messaging, games, productivity tools, among many others. Accessing the Web with mobile devices, either through a browser or a native appli...

Automated accessibility evaluation will have an increasingly important role in the near future due to legal requirements to monitor the accessibility of the websites of public bodies in the European Union. However, automated evaluation tools are still limited in the scope of the conformance testing they are able to perform. Future solutions resorti...

Non-pharmacological interventions for people with dementia benefit from the usage of personalized materials. These are not always easy to obtain. In a set of formative studies, we looked at how clinical staff and families recur to the usage of biographical elements to stimulate and foster the self-identity of people with dementia. Results showed th...

Unauthorized physical access to personal devices by people known to the owner of the device is a common concern, and a common occurrence. But how do people experience incidents of unauthorized access? Using an online survey, we collected 102 accounts of unauthorized access. Participants wrote stories about past situations in which either they acces...

Understanding what role a visual element plays in a web page can have a significant impact in the accessibility of that page. From an accessibility conformance testing perspective, several WCAG techniques require role identification of some visual elements during the testing process. This has prevented automatic accessibility evaluation tools from...

Despite its many advantages, automated web accessibility evaluation's main limitation is still its inability to assess rules and techniques that require a semantic understanding of the web content. Today, machine learning solutions are available that can interpret different media content with a reasonable degree of confidence. These solutions have...

Non-pharmacological interventions are the most common and arguably most effective for people with dementia. Some of these approaches have been proven to benefit from the usage of biographical or personalized materials. These contents are not always easy to obtain. Alongside, it is a challenge to maintain awareness of what is meaningful for a certai...

Most business process modeling tools used today encourage the rendition of lean, prescribed and clearly coordinated activities, which often clash with far more intricate business realities. This paper evaluates an alternative approach that adopts concepts from storytelling and sense-making theories to elicit process stories. The viability of this a...

Abstract: Introduction: Videogames have been used as tools for training cognitive functions, with both clinical and nonclinical populations. However, the evidence about what makes videogames effective in promoting general or specific cognitive functions is still scarce. Objective: To identify, integrate and summarize knowledge about effective video...

This chapter addresses the design of accessible interfaces. Departing from an analysis of the challenges facing designers of interactive systems that want to create accessible solutions, the chapter presents novel interaction solutions that have high potential to increase the accessibility of future systems. The chapter focuses, in particular, moda...

Facebook accounts are secured against unauthorized access through passwords and device-level security. Those defenses, however, may not be sufficient to prevent social insider attacks, where attackers know their victims, and gain access to a victim's account by interacting directly with their device. To characterize these attacks, we ran two MTurk...

Nowadays, there has been a continual increase in life expectancy in almost all countries of the world and the number of elderly people has grown considerably. However, the number of professional support (e.g. caregivers) to people with dementia is not growing proportionally. One of the possible ways to ease the overburden of these professionals is...

Touch-enabled devices have a growing variety of screen sizes; however, there is little knowledge on the effect of key size on non-visual text-entry performance. We conducted a user study with 12 blind participants to investigate how non-visual input performance varies with four QWERTY keyboard sizes (ranging from 15mm to 2.5mm). This paper presents...

Nowadays, there has been a continual increase in life expectancy in almost all countries of the world and the number of elderly people has grown considerably. However, the number of professional support (e.g. caregivers) to people with dementia is not growing proportionally. One of the possible ways to ease the overburden of these professionals is...

Personal mobile devices keep private information which people other than the owner may try to access. Thus far, it has been unclear how common it is for people to snoop on one another's devices. Through an anonymity-preserving survey experiment, we quantify the pervasiveness of snooping attacks, defined as "look-ing through someone else's phone wit...

This paper presents a study assessing the effect of development technology choices on the accessibility quality of web pages. We used an off-the-shelf tool to identify technologies over a set of 1669 pages, each from a different domain. We have focused, in particular, in programming languages, Web and JavaScript frameworks, and content management s...

The search for usable systems has highlighted design criteria like adaptiveness or accessibility support. The systemic view of interaction, encompassing the human user, artifacts, language, methodology and training, influenced the design principles of past and current systems. How-ever, users have been taken as black boxes, communicating with the m...

A doença de Alzheimer afeta cerca de 1% da população portuguesa e duplicará nas próximas décadas. É uma doença crónica e incurável cujo tratamento farmacológico só desacelera a sua evolução, podendo ser complementado com atividades de estimulação. A estimulação cognitiva, nomeadamente a terapia de reminiscência, e a orientação para a reali-dade dim...

Authentication mechanisms are useful when a device is lost or stolen, but ineffective when it comes to preventing friends and family from snooping through contents. Most unlock authentication methods are vulnerable to observation attacks than can easily be performed by those in a close social circle. Moreover, unlock authentication does not address...

Cognitive behavioral therapy and social competences and skills training sometimes rely on in-situ activities to improve the patients’ condition. As the process evolves, therapists concede some autonomy to patients, allowing them to carry out those activities without the need for the former’s presence. The ability to remotely track patient’s activit...

As people store more personal data in their smartphones, the consequences of having it stolen or lost become an increasing concern. A typical counter-measure to avoid this risk is to set up a secret code that has to be entered to unlock the device after a period of inactivity. However, for blind users, PINs and passwords are inadequate, since entry...

In today's culture, television is still a central part of everyone's life. Like everyone else, blind and partially sighted persons want to watch TV and be part of the trend. With the TV signal digitization and the current market growth of connected TVs, we envision the appearance of accessibility barriers for visually impaired persons. As a first s...

When teaching in university courses, one of the main problems is the students' lack of motivation for everyday study. Learning management systems (LMS) provide a set of tools that students must handle to follow the course, but usually students need additional aid to effectively mastering these tools. We present here Merlin-Know, a new module for th...

In Computer Science Education there is a tendency to implement active learning paradigms where students are the focus of the educational process. An instantiation of these learning methods are gaming environments. We present ProGames, a system for learning programming skills through a leveled set of visually-attractive and interactive programming g...

This paper presents an experimental study designed to understand the accessibility differences between the desktop and mobile representations of a Web page. We performed an automatic evaluation of both representations of the home pages of 474 Web sites, using the QualWeb evaluator. We also categorized the pages according to their building methodolo...

This paper presents a design space for persuasive cooperative persuasive interactions for mobile exertion applications. This type of software bridges entertainment with workout activities, providing users with intuitive and fun ways to track their performances. Persuasion and, in particular, cooperative interactions play a pivotal role in user moti...

In the aftermath of natural disasters, members of the affected com-munities are often the de facto first responders. Local volunteers can respond quickly, are strongly motivated, and have the necessary ground knowledge. However, their search and rescue efforts may be misdirected in the absence of information about the location and status of victims...

In Computer Science Education there is a tendency to implement active learning paradigms where students are the focus of the educational process. An instantiation of these learning methods are gaming environments. We present ProGames, a system for learning programming skills through a leveled set of visually-attractive and interactive programming g...

Growing usage of interactive systems in the public space has highlighted the prevalence of conflicts between desired functionality and maintenance of privacy/social comfort. This has inspired researchers and practitioners, in communities concerned with usable security, wearable and mobile interfaces, natural user interfaces, accessibility and socia...

In close relationships, snooping on another's mobile device is commonly regarded as an invasion of privacy. The prevalence of such behavior is, however, difficult to assess. We compared two in-person survey techniques, one in which the question about snooping behavior is posed directly, and one in which strong anonymity controls are employed. Resul...

This paper presents an experimental study designed to understand the differences of performing personalized Web accessibility evaluations or generic evaluations. We used the WaaT evaluator, which can perform personalized WCAG 2.0 based evaluation. We claim that these tools can be used by an individual to understand if a page is accessible to himsel...

The decay of cognitive abilities associated with dementia severely impacts the quality of life of a person and his surrounding ecosystem. First, people with dementia (PwD) increasingly forget the events in their lives leading to depression, isolation and faster cognitive deterioration. Second, their caregivers, besides the emotional burden that hav...

In this paper we report on the design of a support system for autism therapists. The system was co-designed with a team of therapists working with autistic children and supports session management and data collection and analysis. It is integrated with a storytelling interactive environment in the context of improving the social skills of children...

Gesture imitation has recognized benefits as a therapy for children with Autism Spectrum Disorder. Even tough automatic gesture recognition has advanced greatly in the last years, its application in the field of autism therapy has been mostly irrelevant. In this paper we present a solution that: 1) integrates gesture imitation into storytelling the...

The number of people who are suffering from dementia and its most common form Alzheimer, increased significantly during the last years. One of the consequences of the Alzheimer's disease is the social isolation. The patients start to avoid their friends and family. With our project we aim to maintain the patients social active. Our approach is base...

This paper discusses the main differences between humanistic and mechanistic business process modeling. While the mechanistic approach requires strict process formalization, emphasizes technical details, and constrains the modeling task to technology experts, the humanistic approach is more centered on the end-user. We developed a modeling approach...

This paper presents the design process of a geo-referenced communication system which aims at providing technological support to Cognitive Behavioral Therapy and Social Competences and Skills Training therapeutic procedures. The usage of geo-spatial information while communicating between therapists and patients can be critical, particularly in in-...

Blind people typically resort to audio feedback to access information on electronic devices. However, this modality is not always an appropriate form of output. Novel approaches that allow for private and inconspicuous interaction are paramount. In this paper, we present a vibrotactile reading device that leverages the users’ Braille knowledge to r...

Blind people are deprived from a wide set of information about the surrounding environment. This is a reality for places, objects and people. In particular, if social norms are disrespected, the blind person is likely to miss out the presence and absence of people in the same room or passing by. Current mobile devices provide a bundle of sensors th...

Current smartphone authentication methods are known to be susceptible to even rudimentary attacks based on observation. In this paper, we propose an approach to authentication based on rich tapping patterns that addresses this problem. We present a novel tapping detection technique, using a single example as a template. We also report on two user s...

Being the most used method for dissemination of information, especially for public services, it is of paramount importance that the Web is made accessible as to allow all its users to access the content of its pages. In this paper, we evaluated 2250 Governmental Web pages from each one of three different African countries (i.e., Angola, Mozambique...

We present a system for learning programming skills, ProGames, through a leveled set of visually-attractive and interactive programming exercises in Greenfoot, categorized by students likes to offer them solutions to problems they really enjoy or like most. The system has been evaluated during the course 2012-13 in 3 Computer Science Degrees and ou...

This paper discusses a set of interaction patterns encountered during the development of an authoring tool for mobile therapeutic applications. Unlike static paper artefacts, mobile applications can be enriched via the inclusion of complex behaviors. Typical examples include the definition of simple sequential interaction among all screens or the i...

Recent years have witnessed an increasing importance of mobile devices. They pervade people’s everyday lives, not only just in the form of feature phones, but also as smartphones and tablets. Some of these have the computing power of small computers. We are, thus, at the cusp of a fundamental change in how we relate to information and others, acces...

With the increasing popularity of Rich Internet Applications (RIAs), several challenges arise in the area of web accessibility evaluation. A particular set of challenges emerges from RIAs dynamic nature: original static Web specifications can change dramatically before being presented to the end user; a user triggered event may provide complete new...

Mobile interaction presents challenges that go beyond the traditional desktop contexts. These difficulties become even greater when considering people with disabilities or people without disabilities that experience situational impairments. Further, mobile devices and interfaces have been evolving at an astonishing rate which leads to increasing di...

This paper presents a research which aimed at exploring the effects that videogame temporary reinforcements (commonly known in the domain as power-ups or bonuses) have on players from a physiological and performance perspective. We specifically address this type of mechanic from a persuasion point-of-view, questioning whether the knowledge of the e...

The accessibility evaluation of Web applications has been gaining momentum in previous years. Several guidelines and systems are now available to assess the accessibility of a Web page. However, these guidelines have been show to be inadequate when assessing dynamic Web applications. Furthermore, when considering adaptive Web applications, another...

We present DETACH, an authoring tool which allows therapists to design and deploy digital artefacts for cognitive behavioral therapy procedures. The system potentiates the creation of mobile applications by choosing screen designs from a limited template set based on existing therapeutic paper forms. Screen transitions can be customized according t...

This paper presents an exploration into the effects of specific types of persuasive technology in videogames according to a performance and a physiological perspective. Persuasive mechanisms are often employed to change the behavior of a determined person during a known time frame. In videogames, these approaches are expected to produce results in...

The Web has been growing in size and complexity and is used for the most diverse activities in our everyday life, becoming almost indispensable. Besides, Web applications are becoming more popular, and consequently used by a wide range of people. Thus, it is important to evaluate the accessibility of those applications to guarantee that everyone ca...

This paper presents the design of a puzzle game for the Android platform also shows a study on puzzle solving strategies across different interaction modalities and showcases a player performance analysis in each identified strategy. Solving puzzles is among the oldest challenges and entertainment activities available to us. However, despite major...

This paper presents a study on privacy and secrecy requirements that users feel while in the presence of other people. They are viewed as issues of a social activity and pertain to the desire that the content of messages or the act of writing or reading them is not perceived by others. We assess the needs for privacy according to the message's them...

This paper presents the design of a puzzle game for the Android platform along with a study on puzzle solving strategies across different interaction modalities. Solving puzzles is among the oldest challenges and entertainment activities available to us. However, despite major technological advances, the design of such games has never provided indi...

The videogame industry has suffered significant modifications in the last years, broadening its horizons towards a more casual market. This market expansion not only brings new opportunities from an interaction point-of-view, but also new challenges with the inclusion of users who are not accustomed to these games. This paper presents part of an on...

In the videogame industry, designers have always explored techniques which provide incentives to keep the players' interest and temporarily boost their performance to accomplish the game's goals. Current literature and research is yet to properly assess the effects this type of mechanic has on players. Taking inspiration from other domains, we pres...

Modern Web sites use several techniques (e.g. DOM manipulation) that allow for the injection of new content into their Web pages (e.g. AJAX), as well as manipulation of the HTML DOM tree. This has the consequence that the Web pages that are presented to users (i.e. after browser processing) are different from the original structure and content that...

In the last years, TVs have become platforms providing content and entertainment services, such as video on demand, interactive advertising or so-cial networking. Often, these services are Web based applications that run of connected TVs or set-top boxes. Given TV's wide reach, it is paramount TV applications are designed so that information can be...

The paper presents a new metric and a framework to assess the effort of repairing the accessibility of a Web site. For that all the HTML elements of all the pages of a site are considered, excluding those that are duplicated. The rationale is that those elements are originated in a reusable construct, such as a template and, therefore, need to be c...

Mobile devices have shown to be useful tools in supporting various procedures and therapy approaches for different purposes. However, when applied to children, particular care has to be taken, considering both their abilities and their acceptance towards the used approaches. In this paper we present mobile applications, designed specifically for ch...

The Web has been growing in size and complexity and is used for the most diverse activities in our every day life, becoming almost indispensable. Besides, Web applications are becoming more popular, and consequently used by a wide range of people. Thus, it is important to evaluate the accessibility of the new Rich Internet Applications (RIA) to gua...

This paper details a comparative experimental study to understand the difference of the Web's accessibility properties regarding two different evaluation approaches: using WCAG 2.0 techniques and targeting the pages as they reach the browser; using WCAG 2.0, but evaluating the pages after the browser processing, thus as they will be delivered to th...

This paper presents Augmento, a system which aims at providing individuals with an asynchronous approach of reinforcing the bonds with their relatives by sharing emotions when they are in the vicinity of places which hold special memories of their lives. Augmento capitalizes on existing technologies to accomplish its goal, ranging from the usage of...

The videogame industry has suffered significant modifications in the last years, broadening its horizons towards a more casual market. This market expansion not only brings new opportunities from an interaction point-of-view, but also new challenges with the inclusion of users who are not accustomed to these games. This paper presents part of an on...