Handling ambiguous user input on touchscreen kiosks

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2005.Includes bibliographical references (p. 87-94).Touchscreen kiosks are becoming an increasingly popular means of providing a wide arrange of services to the public. However, the principal drawback of these types of systems lies within the elevated error rates due to finger imprecision and screen miscalibration. These issues become worrisome, considering the greater responsibilities and reliance placed upon touchscreens. This thesis investigates two novel techniques that attempt to alleviate these interaction problems. The first technique, predictive pointing, incorporates information regarding past interactions and an area cursor (which maps the user's touch to a circular area rather than a single point) to provide a better estimate of the intended selection. The second technique, gestural drawing, allows users to draw particular shapes onscreen to execute actions as an alternative means of input that is largely unaffected by issues of miscalibration. Results from a user study indicated that both techniques provided significant advantages in not only lowering error rates, but also improving task completion times over traditional tasks of target selection.by Christopher K. Leung.M.Eng

Current state of digital signal processing in myoelectric interfaces and related applications

This review discusses the critical issues and recommended practices from the perspective of myoelectric interfaces. The major benefits and challenges of myoelectric interfaces are evaluated. The article aims to fill gaps left by previous reviews and identify avenues for future research. Recommendations are given, for example, for electrode placement, sampling rate, segmentation, and classifiers. Four groups of applications where myoelectric interfaces have been adopted are identified: assistive technology, rehabilitation technology, input devices, and silent speech interfaces. The state-of-the-art applications in each of these groups are presented.Peer reviewe

A Domain Independent Framework for Developing Knowledge Based Computer Generated Forces

Computer Generated Forces (CGFs) are important players in Distributed Interactive Simulation (DIS) exercises. A problem with CGFs is that they do not exhibit sufficient human behaviors to make their use effective. The SOAR approach has yielded a human cognitive model that can be applied to CGFs, but this is extremely complex. The product of the research reported in this thesis is a much less complex behavioral framework for a CGF that is easy to validate, revise, and maintain. To support this, an existing, domain independent CGF architecture is discussed and applied to an experimental CGF. Techniques for modeling the knowledge and behaviors of any CGF via semantic nets are presented. A process for transforming the semantic nets into fuzzy controllers is outlined, and pertinent issues regarding fuzzy controllers are discussed. Lastly, a method for making time critical decisions via fuzzy logic is presented

CHORUS Deliverable 2.1: State of the Art on Multimedia Search Engines

Based on the information provided by European projects and national initiatives related to multimedia search as well as domains experts that participated in the CHORUS Think-thanks and workshops, this document reports on the state of the art related to multimedia content search from, a technical, and socio-economic perspective. The technical perspective includes an up to date view on content based indexing and retrieval technologies, multimedia search in the context of mobile devices and peer-to-peer networks, and an overview of current evaluation and benchmark inititiatives to measure the performance of multimedia search engines. From a socio-economic perspective we inventorize the impact and legal consequences of these technical advances and point out future directions of research

Tablet Applications for the Elderly: Specific Usability Guidelines

While the world population is aging, the technological progress is steadily increasing. Smartphones and tablets belong to a growing market and even more people aged 65 and above are using such touch devices. However, with advancing age normal cognitive, sensory, perceptual and motor changes influence psychological and physical capabilities and therefore the way the elderly are able to use tablet-applications. When designing tablet-applications for the elderly developers have to be supported in understanding these capabilities. Therefore, this thesis provides a comprehensive compilation of usability guidelines in order to develop user-friendly tablet-applications for older people. The development and testing of an exemplary tablet-application within this thesis shows how these guidelines can be brought into practice and how this realization is evaluated by test persons in this age group

The role of HCI in the construction of disability

As a discipline concerned with the design, evaluation and implementation of interactive computing systems for human use, and with the study of major phenomena surrounding them, human computer interaction (HCI) is involved in the phenomenon of disability. For an interaction between humans and computers to take place, there should be an interface mediating between both parties. The design of such an interface may inadvertently impose access barriers to some people. HCI literature addresses the relationship between the theory and practice of HCI and disability from different angles, some of which are diametrically opposed. This thesis explores three modern conceptions, or models, of disability — the individualistic medical, the biopsychosocial and the social models —, investigates which model predominates in the HCI literature, and analyzes why choosing a particular model may determine and constrain the classes of problems that can be identified during a solution discovery process. Departing from HCI’s traditional discourse, which interprets the phenomenon of disability as a problem in the human body, the author, leading a team of engineers and psychologists, carried out a project in a school for children with cerebral palsy. The project was aimed to improve different areas of child development, using non conventional user interfaces — i.e. user interfaces that use other input/output devices than the keyboard, mouse or screen. After two years working directly within the field of operations”, the author had the opportunity to contrast the theory underpinning HCI’s methods with real practice and to expand his understandings about the relationships between HCI and disability. The research process involved an action research approach, which allowed the author and the team of experimenters to formulate new hypotheses as they learned more about the context, to review the process and, ultimately and most importantly,to readapt their actions to better serve the end beneficiaries. The experiences and learnings gathered throughout the process have been included in this thesis as a case study, for the purpose of helping HCI researchers embarking on projects relatable to the one described. Finally, the author urges the HCI community to update its discourse and to connect it with the vast literature related to modern conceptions of the phenomenon of disability

Students´ language in computer-assisted tutoring of mathematical proofs

Truth and proof are central to mathematics. Proving (or disproving) seemingly simple statements often turns out to be one of the hardest mathematical tasks. Yet, doing proofs is rarely taught in the classroom. Studies on cognitive difficulties in learning to do proofs have shown that pupils and students not only often do not understand or cannot apply basic formal reasoning techniques and do not know how to use formal mathematical language, but, at a far more fundamental level, they also do not understand what it means to prove a statement or even do not see the purpose of proof at all. Since insight into the importance of proof and doing proofs as such cannot be learnt other than by practice, learning support through individualised tutoring is in demand. This volume presents a part of an interdisciplinary project, set at the intersection of pedagogical science, artificial intelligence, and (computational) linguistics, which investigated issues involved in provisioning computer-based tutoring of mathematical proofs through dialogue in natural language. The ultimate goal in this context, addressing the above-mentioned need for learning support, is to build intelligent automated tutoring systems for mathematical proofs. The research presented here has been focused on the language that students use while interacting with such a system: its linguistic propeties and computational modelling. Contribution is made at three levels: first, an analysis of language phenomena found in students´ input to a (simulated) proof tutoring system is conducted and the variety of students´ verbalisations is quantitatively assessed, second, a general computational processing strategy for informal mathematical language and methods of modelling prominent language phenomena are proposed, and third, the prospects for natural language as an input modality for proof tutoring systems is evaluated based on collected corpora