John M. Flach

Graphical displays: implications for divided attention, focused attention, and problem solving

When completing tasks in complex, dynamic domains observers must consider the relationships among many variables (e.g., integrated tasks) as well as the values of individual variables (e.g., focused tasks). A critical issue in display design is whether or not a single display format can achieve the dual design goals of supporting performance at both types of tasks. We consider this issue from a variety of perspectives. One relevant perspective is the basic research on attention and object perception, which concentrates on the interaction between visual features and processing capabilities. The principles of configurality are discussed, with the conclusion that they support the possibility of achieving the dual design goals. These considerations are necessary but not sufficient for effective display design. Graphic displays map information from a domain into visual features; the tasks to be completed are defined in terms of the domain, not in terms of the visual features alone. The implications of this subtle but extremely important difference are discussed. The laboratory research investigating alternative display formats is reviewed. Much like the attention literature, the results do not rule out the possibility that the dual design goals can be achieved.

SITUATION AWARENESS: PROCEED WITH CAUTION

Situation awareness (SA) is a relatively new concept that has captured the imagination of the human factors community. This new concept is considered in the light of Benton J. Underwoods discussion about psychological concepts. In particular the distinction between SA as a phenomenon description (Level 2 concept) and SA as a causal agent (Level 3 concept) is discussed. The argument that SA is valuable as a phenomenon description draws attention to the intimate interactions between human and environment in determining meaning (or what matters) and reflects an increased appreciation for the intimate coupling between processing stages (e.g., perception, decision, and action) within closed-loop systems. However, I caution against considering SA as a causal agent. When SA is considered to be an object within the cognitive agent, there is a danger of circular reasoning in which SA is presented as the cause of itself. As a causal explanation, SA is a simple, easy-to-understand wrong answer that, in the end, will be an obstacle to research. As a phenomenon description, SA invites further research to discover causal relationships between the design of human-machine systems and the resulting performance.

Sources of Optical Information Useful for Perception of Speed of Rectilinear Self-Motion

Magnitude judgments of the speed of self-motion were examined. The principal independent variables were edge rate, global optical flow rate, and the type of texture (grid or dot). Results indicated that edge rate and global optical flow rate had additive effects on magnitude judgments, with edge rate accounting for a larger portion of the variance. Effects were independent of texture type. Secondary variables examined were viewing condition and task load. Attempts were made to control the availability of flatness cues. Evidence indicates that the effectiveness of global optical flow rate varied with the control of flatness cues. A secondary running auditory Sternberg task was used to prevent edge counting; the presence of this task did not reduce the effect of edge rate. These results replicate and extend previous work by D. H. Owen and colleagues.

Monocular optical constraints on collision control.

A simulated ball-hitting task was used to explore the optical basis for collision control. Ball speed and size were manipulated in Experiments 1 and 2. Results showed a tendency for participants to respond earlier to slower and larger balls. Early in practice, participants would consistently miss the slowest and largest balls. Experiments 3 and 4 examined performance as a function of the range of speeds. Performance for identical speeds differed depending on whether the speeds were fastest or slowest within a range. Asymmetric transfer between the 2 ranges of speeds showed that those trained with slow speeds were very successful when tested with a faster range of speeds. Those trained with fast speeds did not do as well when tested on slower speeds. The pattern of results across 4 experiments suggests that participants were using optical angle and expansion rate as separate degrees of freedom for solving the collision task.

MGA: a decision support system for complex, incompletely defined problems

Modeling-to-generate alternatives (MGA) is a technique for using mathematical programming models to generate a small number of different solutions for the decision maker to consider when dealing with complex, incompletely defined problems. The logic of MGA is presented in the context of concerns about the limitations of mathematical models and the human decision-makers who use them. Arguments and experimental evidence are presented to support the assumption that the human-machine decision-making system will perform better when the human is presented with a few different alternatives than when presented with a homogeneous set of alternatives, as might result from sensitivity analysis. >

Local applications of the ecological approach to human-machine systems

Contents: Preface. W. Schiff, W. Arnone, Perceiving and Driving: Where Parallel Roads Meet. S.B. Flynn, T.A. Stoffregen, Perceiving and Avoiding Rollover in Agricultural Tractors. J.M. Flach, R. Warren, Low-Altitude Flight. J. Grosz, R.T. Rysdyk, R.J. Bootsma, J.A. Mulder, J.C. van der Vaart, P.C.W. van Wieringen, Perceptual Support for Timing of the Flare in the Landing of an Aircraft. G.E. Riccio, Coordination of Postural Control and Vehicular Control: Implications for Multimodal Perception and Simulation of Self-Motion. G.J.F. Smets, Designing for Telepresence: The Delft Virtual Window System. J.P. Hansen, Representation of System Invariants by Optical Invariants in Configural Displays for Process Control. L.A. Whitaker, V.G. CuQlock-Knopp, Human Exploration and Perception in Off-Road Navigation. H.L. Pick, M.R. Heinrichs, D.R. Montello, K. Smith, C.N. Sullivan, W.B. Thompson, Topographic Map Reading. R.R. Hoffman, R.J. Pike, On the Specification of the Information Available for the Perception and Description of the Natural Terrain. G. Klein, B.W. Crandal, The Role of Mental Simulation in Problem Solving and Decision Making. M.F. Young, M.D. McNeese, A Situated Cognition Approach to Problem Solving. L.D. Segal, Designing Team Workstations: The Choregraphy of Teamwork. P.N. Kugler, G. Lintern, Risk Management and the Evolution of Instability in Large-Scale, Industrial Systems.

The Reality of Experience: Gibson's Way

This paper considers some first principles that might provide a basis for an objective science of experience (presence or immersion). Dimensions that are considered include classical Newtonian measures of the distal stimulus, changes in neural mechanisms reflecting the proximal stimulus, information theoretic measures of the statistical properties of events, and functional properties related to intentions and abilities. Gibsons ecological framework is suggested as a promising functional approach for defining the reality of experience in relation to the problem of designing virtual environments. This approach emphasizes the tight coordination between perception and action and fixes the measurement coordinate system relative to the capacity for action.

Theoretical Foundations for a Total Energy-Based Perspective Flight-Path Display

One of the most difficult aspects of manually controlled flight is the coupling between the control over the aircraft speed and altitude. These states cannot be changed independent of each other through the aircraft control devices, the elevator and the throttle. Rather, to effectively change an aircrafts speed and altitude, the controls have to be coordinated. The mediating mechanism that underlies the coordination of the controls is the management of the aircrafts energy state. This article shows that the abstraction hierarchy (AH; Rasmussen, 1986) framework can be effectively used to gain more insight into the underlying structure of the aircraft energy management problem. The derived AH representation is based on the analysis of the energy constraints on the control task. It reveals the levels of abstraction necessary to link the aircrafts physical controls to the speed and altitude goals and also how the aircraft energy is a critical mediating state of the control problem. Energy awareness can be increased by presenting explicit energy management information. The powerful and novel concepts of the total energy reference profile and energy angle are introduced in this article and applied in the context of a perspective flight-path display. The resulting display presents energy management information fully integrated with the tunnel-in-the-sky display and reveals 5 new and important energy cues, intuitively linking the controls and the goals.

Perceptual-Motor Coordination in an Endoscopic Surgery Simulation

AbstractBackground: This study examined perceptual-motor coordination with an apparatus that simulated a situation representative of endoscopic surgery. Methods: Participants were trained with one arrangement of the apparatus, then tested with an alternative arrangement in which either the positions of the camera, the surgeon, or the objects in the surgical field were altered. Results: Results showed that changes of either the cameras position or the surgeons position disrupted performance. However, when the camera and surgeon positions were changed together, skilled performance was maintained. Conclusions: This suggests that skill depends on a consistent mapping between the virtual hands and eyes, but not on the particular visual or motor orientations. The results suggest that movements of the camera during surgery can disrupt coordinated action. Also, in the design of training simulators, the mapping between camera and instruments may be more important than the static appearance of the displays or the topology of the movements.

Management of Test Results in Family Medicine Offices

PURPOSE We wanted to explore test results management systems in family medicine offices and to delineate the components of quality in results management. METHODS Using a multimethod protocol, we intensively studied 4 purposefully chosen family medicine offices using observations, interviews, and surveys. Data analysis consisted of iterative qualitative analysis, descriptive frequencies, and individual case studies, followed by a comparative case analysis. We assessed the quality of results management at each practice by both the presence of and adherence to systemwide practices for each results management step, as well as outcomes from chart reviews, patient surveys, and interview and observation notes. RESULTS We found variability between offices in how they performed the tasks for each of the specific steps of results management. No office consistently had or adhered to office-wide results management practices, and only 2 offices had written protocols or procedures for any results management steps. Whereas most patients surveyed acknowledged receiving their test results (87% to 100%), a far smaller proportion of patient charts documented patient notification (58% to 85%), clinician response to the result (47% to 84%), and follow-up for abnormal results (28% to 55%). We found 2 themes that emerged as factors of importance in assessing test results management quality: safety awareness—a leadership focus and communication that occurs around quality and safety, teamwork in the office, and the presence of appropriate policies and procedures; and technological adoption—the presence of an electronic health record, digital connections between the office and testing facilities, use of technology to facilitate patient communication, and the presence of forcing functions (built-in safeguards and requirements). CONCLUSION Understanding the components of safety awareness and technological adoption can assist family medicine offices in evaluating their own results management processes and help them design systems that can lead to higher quality care.