skip to main content


Search for: All records

Creators/Authors contains: "Khalaf, Ahmed S."

Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?

Some links on this page may take you to non-federal websites. Their policies may differ from this site.

  1. null (Ed.)
  2. Gesture recognition devices provide a new means for natural human-computer interaction. However, when selecting these devices to be used in games, designers might find it challenging to decide which gesture recognition device will work best. In the present research, we compare three vision-based, hand-gesture devices: Leap Motion, Microsoft’s Kinect, and Intel’s RealSense. The comparison provides game designers with an understanding of the main factors to consider when selecting these devices and how to design games that use them. We developed a simple hand-gesture-based game to evaluate performance, cognitive demand, comfort, and player experience of using these gesture devices. We found that participants preferred and performed much better using Leap Motion and Kinect compared to using RealSense. Leap Motion also outperformed or was equivalent to Kinect. These findings were supported by players’ accounts of their experiences using these gesture devices. Based on these findings, we discuss how such devices can be used by game designers and provide them with a set of design cautions that provide insights into the design of gesture-based games. 
    more » « less
  3. Composite wearable computers combine multiple wearable devices to form a cohesive whole. Designing these complex systems and integrating devices to effectively leverage their affordances is nontrivial. To inform the design of composite wearable computers, we undertook a grounded theory analysis of 84 wearable input devices drawing from 197 data sources, including technical specifications, research papers, and instructional videos. The resulting prescriptive design framework consists of four axes: type of interactivity, associated output modalities, mobility, and body location. This framework informs a composition-based approach to the design of wearable computers, enabling designers to identify which devices fill particular user needs and design constraints. Using this framework, designers can understand the relationship between the wearable, the user, and the environment, identify limitations in available wearable devices, and gain insights into how to address design challenges developers will likely encounter. 
    more » « less
  4. Gesture recognition devices provide a new means for natural human-computer interaction. However, when selecting these devices for games, designers might find it challenging to decide which gesture recognition device will work best. In the present research, we compare three vision-based, hand gesture devices: Leap Motion, Microsoft's Kinect, and Intel's RealSense. We developed a simple hand-gesture based game to evaluate performance, cognitive demand, comfort, and player experience of using these gesture devices. We found that participants' preferred and performed much better using Leap Motion and Kinect compared to using RealSense. Leap Motion also outperformed or was equivalent to Kinect. These findings suggest that not all gesture recognition devices can be suitable for games and that designers need to make better decisions when selecting gesture recognition devices and designing gesture based games to insure the usability, accuracy, and comfort of such games. 
    more » « less
  5. Composite wearable computers consist of multiple wearable devices connected together and working as a cohesive whole. These composite wearable computers are promising for augmenting our interaction with the physical, virtual, and mixed play spaces (e.g., mixed reality games). Yet little research has directly addressed how mixed reality system designers can select wearable input devices and how these devices can be assembled together to form a cohesive wearable computer. We present an initial taxonomy of wearable input devices to aid designers in deciding which devices to select and assemble together to support different mixed reality systems. We undertook a grounded theory analysis of 84 different wearable input devices resulting in a design taxonomy for composite wearable computers. The taxonomy consists of two axes: TYPE OF INTERACTIVITY and BODY LOCATION. These axes enable designers to identify which devices fill particular needs in the system development process and how these devices can be assembled together to form a cohesive wearable computer. 
    more » « less
  6. In distributed multiplayer games, it can be difficult to communicate strategic information for planning game moves and player interactions. Often, players spend extra time communicating, reducing their engagement in the game. Visual annotations in game maps and in the gameworld can address this problem and result in more efficient player communication. We studied the impact of real-time feedback on planning annotations, specifically two different annotation types, in a custom-built, third-person, multiplayer game and analyzed their effects on player performance, experience, workload, and annotation use. We found that annotations helped engage players in collaborative planning, which reduced frustration, and shortened goal completion times. Based on these findings, we discuss how annotating in virtual game spaces enables collaborative planning and improves team performance. 
    more » « less
  7. A primary component of disaster response is training. These educational exercises provide responders with the knowledge and skills needed to be prepared when disasters happen. However, traditional training methods, such as high-fidelity simulations (e.g., real-life drills) and classroom courses, may fall short of providing effective and cost-efficient training that is needed for today’s challenges. Advances in technology open a wide range of opportunities for training using computer-mediated simulations and exercises. These exercises include the use of mixed reality games and wearable computers. Existing studies report on the usefulness of these technologies for training purposes. This review paper synthesizes prior research and development of disaster response simulations and identifies challenges, opportunities, and lessons learned. Through this review, we provide researchers and designers with an overview of current practices in designing training simulations and contribute practical insights into the design of future disaster response training. 
    more » « less
  8. The proliferation of unmanned aerial systems (i.e., drones) can provide great value to the future of search and rescue. However, with the increase adoption of such systems, issues around hybrid human-drone team coordination and planning will arise. To address these early challenges, we provide insights into the development of testbeds in the form of mixed reality games with simulated drones. This research presents an architecture to address challenges and opportunities in using drones for search and rescue. On this architecture, we develop a mixed reality game in which human players engage with the physical world and with gameplay that is purely virtual. We expect the architecture to be useful to a range of researchers an practitioners, forming the basis for investigating and training within this unique, new domain. 
    more » « less