Allen R. Revels

Application of Information Visualization Principles at Various Stages of System Development

Designing and developing effective information visualizations requires a systematic approach. This Practitioner Paper identifies how innovative information visualizations can be integrated into standard systems development processes. While information visualizations already exist for the design of user interfaces, new methods frequently offer further improvement in information displays. Designers should consider incorporating these advancements wherever possible. The Systems Development Process provides the structure necessary to integrate new information visualizations throughout the design process. This paper describes specific examples whereby innovative information visualization methods were integrated into a USAF R&D design effort during several phases of its development. Information visualization methods include use of micro/macro salience displays, visual language, and axiomatic designs. This approach not only improved the quality of the user displays through advancing information visualization techniques, it also minimized design modifications through use of the system development processes.

Comparison of Hands-Free versus Conventional Wearable Computer Control for Maintenance Applications

Past research on wearable computers for maintenance applications has focused on developing displays and presentation formats. This study emphasized wearable computer control technologies. Alternative control technologies were compared with standard and voice controls. Twelve subjects performed a synthetic maintenance task using three control device combinations for three different types of input. Time and error data were collected. The results show that for pointer movement, standard controls took significantly longer than voice. For discrete input, standard controls required significantly more time than voice and alternative controls. However, there were no significant time differences among controllers for text entry fill-in. Error results showed no significant differences. This research suggests that alternative and voice controls provide similar performance levels and both are superior to standard controls. In environments with changing noise spectra and noise levels such as a flight line, the alternative control suite provides hands-free control that complements voice without sacrificing performance.

Human Interaction with Wearable Computer Systems: A Look at Glasses-Mounted Displays

With the advancement of technology and the information explosion, integration of the two into performance aiding systems can have a significant impact on operational and maintenance environments. The Department of Defense and commercial industry have made great strides in digitizing and automating technical manuals and data to be presented on performance aiding systems. These performance aides are computerized interactive systems that provide procedures on how to operate and maintain fielded systems. The idea is to provide the end-user a system which is compatible with their work environment. The purpose of this paper is to show, historically, the progression of wearable computer aiding systems for maintenance environments, and then highlight the work accomplished in the design and development of glasses- mounted displays (GMD). The paper reviews work performed over the last seven years, then highlights, through review of a usability study, the advances made with GMDs. The use of portable computing systems, such as laptop and notebook, computers, does not necessarily increase the accessibility of the displayed information while accomplishing a given task in a hands-busy, mobile work environment. The use of a GMD increases accessibility of the information by placing it in eye sight of the user without obstructing the surrounding environment. Although the potential utility for this type of display is great, hardware and human integration must be refined. Results from the usability study show the usefulness and usability of the GMD in a mobile, hands-free environment.

Determining Voice Strategies for Hands-Free Human-Computer Interaction

This Practitioner Paper examines a cost effective and efficient method to determine voice command strategies for hands-free controls when interacting with computer systems. Specifically, this method is applied to determining the combined use of voice commands and a head-tracking device as an alternative user interface for accessing digitized aircraft technical manuals. Aircraft maintainers from the Springfield, OH Air National Guard F-16 facility and the 445th C-141 Air Force Reserve Unit served as subjects. User strategies appeared to follow on-screen interface characteristics and the users experience level with computers. Generally, unlabeled icons and buttons elicited a point-and-click strategy, while labeled links elicited voice-only commands. Users with increased familiarity with Windows-based interfaces were prone to a point-and-click strategy, while novices were likely to attempt various function oriented voice commands. Due to the observed user strategies, several issues were identified and a series of recommendations are presented which address the strategic application of a voice command vocabulary to a hands-free user interface.

Reducing Cannon Plug Connector Pin Selection Time and Errors Through Enhanced Data Presentation Methods.

This research investigated the effects of data presentation formats on technician performance when maintenance procedures are presented on a monocular, head-mounted display (HMD). The maintenance task was a continuity check performed by identifying, selecting, and testing pairs of cannon plug connector pins. Two formats were used to present task procedure information to the subject: a format that mimicked the standard technical procedure manual, including the textual and graphical characteristics; a format which provided the same information as the first, while adding visual cues to the graphical portion of the technical information. Two types of cannon plugs were used: ‘few-pin’ plugs (12 and 13 pins) and ‘many-pin’ plugs (55 and 79 pins). United States Air Force (USAF) avionics maintenance technicians stationed atBarksdale Air Force Base, Louisiana served as subjects. Dependent measures were: task completion time, task error rate, and subjective reports on the usability of the information presentation structure and the HMD. Results indicate that in general, technicians perform tasks more quickly and commit fewer errors when using enhanced graphical data presentation methods. Technicians indicated via post test questionnaire that such data formats, and HMDs in general, could be a useful tool in the performance of their maintenance duties.

Performance Testing and Subjective Evaluation: Giving Equal Importance to Both

The key to finding real issues with, and benefits of a product or system is to collect and merge findings from both empirical performance testing and subjective evaluation methods. As practitioners, Human Factors professionals are frequently challenged with identifying cost effective solutions that also meet end-user needs for usability. If the system is not usable from the end-users perspective, performance enhancements cannot be achieved. Likewise, if the system is very usable but does not provide any process improvement, then it is not likely to be purchased. Reconciling and communicating differences in findings between empirical and subjective data is challenging. This paper provides a systematic method for providing value for all product or system users, including individuals with such disparate needs as management and end-users. The paper incorporates recognized usability testing methods for addressing detailed usability concerns, includes a method of systematic testing called the LSF Process, and introduces a means of communicating subjective feedback through cluster graphs.

Evaluation of mobile computing displays

As technology moves toward mobile computing, evaluation of these technologies, such as head-mounted and glasses-mounted displays, and human performance associated with their use in essential to their successful development. This paper presents the results of one such evaluation.

Animation of Pictorial Icons

This laboratory investigation stems from an Air Force command and control research program in which the status of squadrons and individual aircraft in flight is communicated through pictorial icons. The study investigated the use of animation as cue for remembering the status of aircraft presented in a 3 × 3 display of pictorial icons. Pictorial icons were present to participants in both a homogeneous context (all non-animated) and a mixed context of animated and non-animated icons in a crossover design extending over two sessions. Results indicated the animation facilitated memory, but suggest that the effects may be short-lived. Animation is discussed in terms of its possible beneficial effects (saliency, isomorphism, highlighting distinguishing features, and information chunking) as well as its costs.

The Use of Voice and Head-Tracking for Hands-Free Human-Computer Interaction

This Practitioner Paper discusses the second in a series of studies examining the Voice Head Integrated Control (VHIC) suite, which combines use of voice commands and a head-tracking device as an alternative to the mouse and keyboard. This VHIC system is currently being investigated as a hands-free interface for accessing digitized aircraft technical manuals. The present study was conducted to validate the voice command vocabulary and provide an initial evaluation of the VHIC hardware. Aircraft maintainers from the 445th C-141 Air Force Reserve Unit served as subjects. The current study made use of the fully functioning VHIC system, complete with head-tracking and voice recognition capabilities. User strategies followed on-screen interface characteristics and the users experience level with computers. Several error categories were tracked and subjective feedback was collected. A series of recommendations are presented which address the strategic application of the VHIC system in an aircraft maintenance environment.

Glasses Mounted Display Baseline Test: Comparing the GMD to Traditional Displays

The purpose of this test was to compare the performance of the Glasses-Mounted Display (GMD) with a standard desktop monitor. Although standard computers and their displays, such as a notebook computer with a liquid-crystal display (LCD), are appropriate for many applications outside the office, certain factors, such as increased mobility or hands-free requirements, can impede the usability of standard computers. The GMD provides a potential solution to the display requirements associated with these unique situations. The current study used three independent variables to test this: 1) Display (GMD vs. Laptop computer LCD), 2) Data Source (an internal location on the display vs. from a separate, external CRT), and 3) Trial (six total trials). Results were mixed; although the interaction of Display x Data Source indicated the GMD may be useful in applications that involve visual attention switching. Subjective feedback indicated a greater familiarity and comfort level with a laptop computer and its LCD display. However, subjects also recognized the GMDs potential use for tasks involving confined areas, hands-busy operation, and tasks requiring continual switching of attention between the GMD and task environment.