Hendrik Iben

Visual based picking supported by context awareness: comparing picking performance using paper-based lists versus lists presented on a head mounted display with contextual support

Warehouse picking is a traditional part of assembly and inventory control, and several commercial wearable computers address this market. However, head mounted displays (HMDs) are not yet used in these companys products. We present a 16 person user study that compares the efficiency and perceived workload of paper picking lists versus a HMD system aided by contextual cueing. With practice, users of the HMD system made significantly faster picks and made less mistakes related to missing or additional picked items overall.

Evaluation of graphical user-interfaces for order picking using head-mounted displays

Order picking is the process of collecting items from an assortment in inventory. It represents one of the main activities performed in warehouses and accounts for about 60% of the total operational costs of a warehouse. In previous work, we demonstrated the advantages of a head-mounted display (HMD) based picking chart over a traditional text-based pick list, a paper-based graphical pick chart, and a mobile pick-by-voice system. Here we perform two user studies that suggest that adding color cues and context sensing via a laser rangefinder improves picking accuracy with the HMD system. We also examine other variants of the pick chart, such as adding symbols, textual identifiers, images, and descriptions and their effect on accuracy, speed, and subjective usability.

An Abstract User Interface Framework for Mobile and Wearable Devices

In the future, mobile and wearable devices will increasingly be used for interaction with surrounding technologies. When developing applications for those devices, one usually has to implement the same application for each individual device. Thus a unified framework could drastically reduce development efforts. This paper presents a framework that facilitates the development of context-aware user interfaces UIs with reusable components for those devices. It is based on an abstract description of an envisioned UI which is used to generate a context-and device-specific representation at run-time. Rendition in various modalities and adaption of the generated representation are also supported.

The Impact of Different Visual Feedback Presentation Methods in a Wearable Computing Scenario

Interfaces for wearable computing applications have to be tailored to task and usability demands. Critical information has to be presented in a way allowing for fast absorption by the user while not distraction from the primary task. In this work we evaluated the impact of different information presentation methods on the performance of users in a wearable computing scenario. The presented information was critical to fulfill the given task and was displayed on two different types of head mounted displays (HMD). Further the representations were divided into two groups. The first group consisted of qualitative representations while the second group focused on quantitative information. Only a weak significance could be determined for effect the different methods used have on the performance but there is evidence that familiarity has an effect. A significant effect was found for the type of HMD.

A methodical approach to evaluating the use of audio-interfaces for mobile and wearable computing

Audio interfaces for mobile and wearable computing are in an early state of development. User studies concentrate on the usability of audio interfaces as means of interacting with a device but leave out the question of how an audio interface can aid at performing a main task. Studying the impact of audio interfaces in computer aided tasks for wearable and mobile computing will provide guidelines for hands-free interface design and information presentation. To be able to measure the performance a simulated main task is used where varying mental loads can be setup. Providing an index of difficulty for the simulated task, users studies will reveal how effective an audio interface can be used to convey information to aid at a task.

Hardware and Software for Solving the Serious Game Challenge Using Commercial Off-the-Shelf Components and Open Source Software Frameworks

The purpose of this book chapter is to show how to solve the problem of selection of an appropriate hardware and software. This is a challenge for any non-standardized application domain and a problem any research project has when looking for a general purpose solution for a specific problem. Here we target the evaluation of a Reference Rehabilitation Platform (RRP) for Serious Games. One constraint in such a case is that all components should be commercial off-the-shelf during the runtime of the project. Components should be well tested, provide sufficient firmware and documentation for integration and have the potential of becoming a kind of standard in the market. This is essential, as the focus of any such project is the problem solution and its evaluation of the hardware and software. We propose a platform where different Serious Games can be deployed and input devices as bio sensors can be plugged in easily. We developed a solution where these components can be replaced by new components easily without changing the whole architecture. This book chapter addresses technical issues and provides an idea how to integrate Serious Games for rehabilitation purposes as described in the chapter four.