Ilhan Aslan

LOLL io : exploring taste as playful modality

In this paper we describe an exploratory design study of the potentials of taste as a playful interaction modality. We present the design and implementation of LOLLio -- an interactive lollipop that serves as a haptic input device that dynamically changes its taste. We conclude this paper with three basic principles for potential game designs, where we see how the interactive lollipop we have built can foster novel, playful game experiences.

Mid-air Authentication Gestures: An Exploration of Authentication Based on Palm and Finger Motions

Authentication based on touch-less mid-air gestures would benefit a multitude of ubicomp applications, which are used in clean environments (e.g., medical environments or clean rooms). In order to explore the potential of mid-air gestures for novel authentication approaches, we performed a series of studies and design experiments. First, we collected data from more then 200 users during a three-day science event organised within a shopping mall. This data was used to investigate capabilities of the Leap Motion sensor and to formulate an initial design problem. The design problem, as well as the design of mid-air gestures for authentication purposes, were iterated in subsequent design activities. In a final study with 13 participants, we evaluated two mid-air gestures for authentication purposes in different situations, including different body positions. Our results highlight a need for different mid-air gestures for differing situations and carefully chosen constraints for mid-air gestures.

TorqueScreen: Actuated Flywheels for Ungrounded Kinaesthetic Feedback in Handheld Devices

Handheld touch screen based devices, such as smartphones or tablets, typically provide limited haptic feedback. On cur- rent devices, what is visually perceived and what is tactile and kinesthetically felt is semantically uncoupled. In order to improve embodied interaction on handheld screen based devices, new ways to provide richer haptic feedback are re- quired. In this paper, we present TorqueScreen, a prototypi- cal system combining a handheld touch screen device (i.e., a tablet) with an actuated flywheel capable of imposing angular momentum onto the tablet. The TorqueScreen design allows interlinking the movement and physics of virtual objects on the screen with the torque as haptic output imposed on the tablet. We describe the design and implementation of the de- vice, illustrate the resulting design space, and discuss future improvements and potential applications.

GuideMe: A Mobile Augmented Reality System to Display User Manuals for Home Appliances

In this paper we present GuideMe, a mobile augmented reality application that provides assistance in using appliances. In order to explore how users perceive GuideMe, as a design of an interactive and digital manual, we conducted two user studies. We compared GuideMe first with paper-based manuals and then with video-based manuals. Our results indicate that the paper-based manuals were superior regarding typical usability measures (i.e. error rates and completion times). However, participants reported a significantly higher perceived task load when using paper-based manuals. Due to a better user experience, GuideMe was preferred by 9 of 10 participants over paper-based manuals. We present our design in detail and discuss broader implications of designing digital manuals. Furthermore, we introduce a custom format to define manual structures for mobile augmented reality enabled manuals.

The digital bookshelf: decorating with collections of digital books

We describe the Digital Bookshelf (a projector and camera based system) that similar to a physical bookshelf is designed to present a set of books for decorating and self-expression purposes. Digital books in the bookshelf are presented based on meta information (e.g. by price, rating and cover color) to highlight adjacencies and to create a meaningful and aesthetic view. The system makes use of research in serendipity and multivariate statistics to allow the user to browse along flexible paths of adjacent books in a large collection of books. It allows the user to experience how subsets of books create different visual expressions and atmospheres when placed in the bookshelf.

Pre-touch proxemics: moving the design space of touch targets from still graphics towards proxemic behaviors

Proxemic touch targets continuously change in relation to a users hand in mid-air before a physical touch occurs. Previous work has, for example shown that expanding targets are capable to improve target acquisition performance on touch interfaces. However, it is unclear how proxemic touch targets influence user experience (UX) in a broader sense, including hedonic qualities. Towards closing this research gap the paper reports on two user studies. The first study is a qualitative study with five experts, providing in-depth insights on a variety of change-types (e.g., size, form, color) and how they, for example, influence perceived functional and aesthetic qualities of proxemic touch targets. A follow-up user study with 36 participants explores the UX of a proxemic touch target compared to non-proximal versions of the same target. The results highlight a positive significant effect of the proxemic design on both pragmatic and hedonic qualities.

Pen + Mid-Air: An Exploration of Mid-Air Gestures to Complement Pen Input on Tablets

In this paper, we report on a series of studies, exploring the potential of pen and mid-air input on tablets. We describe a field study with an early prototype of a drawing application and follow-up inquiries, such as the development and comparison of gesture sets for pen and mid-air input and pen and multi-touch input with users in a lab environment. Overall, our results suggest that pen and mid-air input should be offered to complement traditional pen and multi-touch input on tablets. We illustrate the final user-defined gestures set for pen and mid-air input and discuss how user preferences of mid-air gestures over touch gestures seem to depend on the complexity of operations and the need of additional menus on the screen.

Towards the counter free store: requirements for mobile sales assistants

Ubiquitous assistants in retail environments can be useful not only for customers but also for salespersons by supporting their work. Providing product and customer information anywhere in the store, is the first step on realizing the vision of the counter free store. To ensure both, usefulness and acceptance of ubiquitous sales assistants, this paper describes in a first step user requirements towards mobile assistants generated in two focus groups with customers and salespersons. We present the identified requirements (e.g., aspects of sales processes, spatial situations, tool mediated cooperation, and information transparency) and discuss how ubiquitous technology should support the high situatedness of the sales situation.

Workload on your fingertips: the influence of workload on touch-based drag and drop

In this paper we explore if it is possible to recognize different cognitive states of a user through analyzing drag and drop behavior on a tablet device. We introduce a modified version of the classic Stroop task, which is a commonly used psychological stressor and investigate how different levels of perceived workload correlate with measures related to fingertip movement during drag and drop. A study with 24 participants is reported, where we were able to replicate the Stroop effect in a touch-based drag and drop task and present 2 measures in fingertip movement that correlate with subjective ratings of workload based on the NASA-TLX questionnaire.

DrinkWatch: A Mobile Wellbeing Application Based on Interactive and Cooperative Machine Learning

We describe in detail the development of DrinkWatch, a wellbeing application, which supports (alcoholic and non-alcoholic) drink activity logging. DrinkWatch runs on a smartwatch device and makes use of machine learning to recognize drink activities based on the smartwatch»s inbuilt sensors. DrinkWatch differs from other mobile machine learning applications by triggering feedback requests from its user in order to cooperatively learn the user»s personalized and contextual drink activities. The cooperative approach aims to reduce limitations in learning performance and to increase the user experience of machine learning based applications. We discuss why the need for cooperative machine learning approaches is increasing and describe lessons that we have learned throughout the development process of DrinkWatch and insights based on initial experiments with users. For example, we demonstrate that six to eight hours of annotated real world data are sufficient to train a reliable base model.