Immanuel Barshi

Effects of Instruction Modality and Readback on Accuracy in Following Navigation Commands

In 3 experiments, the authors simulated air traffic controllers giving pilots navigation instructions of various lengths. Participants either heard or read the instructions; repeated either all, a reduced form, or none of the instructions; and then followed them by clicking on the specified locations in a space represented by grids on a computer screen. Execution performance for visual presentation was worse than it was for auditory presentation on the longer messages. Repetition of the instructions generally lowered execution performance for longer messages, which required more output, especially with the visual modality, which required phonological receding from visual input to spoken output. An advantage for reduced over full repetition for visual but not for auditory presentation was attributed to an enhanced visual scanning process.

Checklist procedures and the cost of automaticity

Automaticity is usually discussed in terms of its benefits. Automaticity has, however, a cost that manifests itself in procedures that are highly routinized but require close attention, such as verbal checklist procedures. In such procedures, errors occur because the routine leads to automaticity. In three paper-and-pen experiments, we tested this manifestation and investigated ways to decrease automaticity in verbal checklist procedures. In the experiments, subjects proofread sets of multiplication problems to detect erroneous operations, simulating the checklist procedure. In Experiments 1 and 2, two conditions were compared: a fixed-order condition (in which each set contained operations in the same order) and a varied-order condition (in which the operations were in a different order in each set). In Experiment 1, proofreading times were measured to establish the role of fixed sequential order as a consistent environment promoting the emergence of automaticity. In Experiment 2, we introduced errors into the material, and in Experiment 3 we introduced “alerting” conditions to interfere with the development of automaticity. The results indicated that the subjects in the varied-order and alert conditions detected significantly more errors than did those in the fixed-order condition. The implications of the findings for current theories of automaticity are discussed as well as those for the design of checklist procedures.

Information Organization in the Airline Cockpit Lessons From Flight 236

We describe the all-engine-out landing of Air Transat Flight 236 in the Azores Islands (August 24, 2001) and use certain aspects of that accident to motivate a conceptual framework for the organization and display of information in complex human-interactive systems. Four hours into the flight, the aircraft experienced unusual oil indications. Two hours later, a fuel system failure led to a full-blown emergency that was not evident to the crew until it was too late. Although all relevant data to avoid the emergency were available to the aircraft computer systems, the design choices made about what to display and how to display it kept the pilots “in the dark.” The framework proposed here consists of six levels, beginning from the extraction of data from physical signals, abstracting from raw data to form visual representations on the user interface, and finally integrating high-level elements and information structures. We illustrate how the framework can be used to analyze some of the shortcomings in current display design, and we discuss some principles of information organization and formal analysis of task logic that might help to improve design. Finally, we sketch a design for a helicopter engine display based on these principles.

The effects of spatial representation on memory for verbal navigation instructions

Three experiments investigated effects of mental spatial representation on memory for verbal navigation instructions. The navigation instructions referred to a grid of stacked matrices displayed on a computer screen or on paper, with or without depth cues, and presented as two-dimensional diagrams or a three-dimensional physical model. Experimental instructions either did or did not promote a three-dimensional mental representation of the space. Subjects heard navigation instructions, immediately repeated them, and then followed them manually on the grid. In all display and experimental instruction conditions, memory for the navigation instructions was reduced when the task required mentally representing a three-dimensional space, with movements across multiple matrices, as compared with a two-dimensional space, with movements within a single matrix, even though the words in the navigation instructions were identical in all cases. The findings demonstrate that the mental representation of the space influences immediate verbatim memory for navigation instructions.

Effects of difficulty, specificity, and variability on training to follow navigation instructions

To study the relative merits of three training principles – difficulty of training, specificity of training, and variability of training – subjects were trained to follow navigation instructions to move in a grid on a computer screen. Subjects repeated and then followed the instructions by mouse clicking on the grid. They were trained, given a short distractor task, and then tested. There were three groups, each receiving different message lengths during training: easy (short lengths), hard (long lengths), and mixed (all lengths), with all subjects given all lengths at test. At test, the mixed group was best on most lengths, the easy group was better than the hard group on short lengths, and the hard group was better than the easy group on long lengths. The results support the advantages of both specificity and variability of training but do not support the hypothesis that difficult training of the form used here would lead to overall best performance at test.

The Operational Context of Procedures and Checklists in Commercial Aviation

To design effective and efficient procedures and checklists, one must take into account the full operational context within which these procedures are embedded. This context is defined by the requirements of the technology, the limitations and capabilities of the human operators, and the constraints and affordances of the operational environment. The complexity of this context arises from the interactions of the human, machine, and environment. We present a model of that operational context, THE Model, that lays the foundations for analyzing each of these elements and their interactions, and illustrate its application through the analysis of an aviation accident.

Using Medieval Architecture as Inspiration for Display Design: Parameter Interrelationships and Organizational Structure

In physical environments such as aerospace and process control, many system components and their associated information are interrelated (e.g., an increase in a chamber temperature results in an increase in its pressure). Displaying interrelationships between individual parameters and also among sets of parameters reveals meaningful information and can help yield understanding about the “big picture,” which operators in complex systems commonly strive for. In this paper, we propose a framework for information organization, discuss a method for computation of such interrelations, and suggest a display organization approach to “house” them. The computation is done using data mining tools and the display organization approach is based on concepts from Islamic medieval architecture. We illustrate these ideas using a helicopter engine display and briefly discuss some of the implications for a holistic display of multiple components and subsystems.

Evaluating Computer Based Training for In Flight Icing

Since the 1940’s a great deal has been learned about aircra ft icing. However, icing accidents continue to occur. Many of these accidents appear to be preventable. Had the pilots known the danger that they were in and had they taken appropriate actions, lives could have been saved. To address this apparent gap in knowledge, a variety of training products have been developed. The most elaborate of these is an interactive computer based training (CBT) product for professional pilots. This CBT was designed both to impart factual knowledge and to enhance pilots’ a bilities to make appropriate operational decisions regarding icing. To accomplish these goals, the educational design of the CBT relied heavily on current work in cognitive science on learning and decision -making. To evaluate the effectiveness of this ap proach, an experiment was conducted. Professional pilots’ factual knowledge of icing and decisions in operational situations were evaluated. Then the participants received one of three educational products: the original CBT, a CBT lacking the interactive exercises, or a booklet on icing. After completing this training, the pilots’ factual knowledge and operational decisions were again evaluated. In addition, subjective evaluations of the materials and evaluations of the pilots’ previous training experie nce were obtained. Preliminary results indicate that the pilots learned more from the CBT and rated it more highly than the other materials and their previous training. This suggests that training based on current knowledge of learning and decision -makin g can be unusually effective and that the time, money, and effort required to produce these products are justified. I. Introduction Over the last 60 years, our understanding of icing has increased substantially. We now know a great deal about the physics, meteorology, and aerodynamic effects of icing. However, the continuing occurrence of icing accidents suggests that this knowledge is not permeating through the aviation community as it should. To address this problem, the Icing Branch at Glenn Research C enter of the National Aeronautics and Space Administration (NASA) developed a series of videos and other training products designed to teach pilots about in -flight icing. ‡ A recent installment in this series is A Pilot’s Guide to In -flight Icing 1 , a comput er -based training program designed for use by pilots without instructor intervention. A Pilot’s Guide to In -flight Icing was designed to provide pilots with the background and procedural knowledge that would lead them to make appropriate operational decis ions about icing. The primary goal of aviation training should be to provide pilots with the knowledge and skills they need to make appropriate operational decisions and to implement those decisions. Pilots must not only learn a great deal of informatio n, they must learn how to apply their knowledge effectively in the operational environment. In this context, cognitive psychologists make a distinction between declarative and procedural knowledge. 2

Does spatial information impact immediate verbatim recall of verbal navigation instructions

The present study addresses the issue of whether spatial information impacts immediate verbatim recall of verbal navigation instructions. Subjects heard messages instructing them to move within a two-dimensional depiction of a three-dimensional space consisting of four stacked grids displayed on a computer screen. They repeated the instructions orally and then followed them manually by clicking with a mouse on the grids. Two groups with identical instructions were compared; they differed only in whether the starting position was indicated before or after the instructions were given and repeated, with no differences in the manual movements to be made. Accuracy on both the oral repetition and manual movement responses was significantly higher when the starting position was indicated before the instructions. The results are consistent with the proposal that there is only a single amodal mental representation, rather than distinct verbal and nonverbal representations, of navigation instructions. The advantage for the before condition was found even for the oral repetition responses, implying that the creation of the amodal representation occurred immediately, while the instructions were being held in working memory. In practical terms, the findings imply that being able to form a mental representation of the movement path while being given verbal navigation instructions should substantially facilitate memory for the instructions and execution of them.

The Human Factors of an early space accident: Flight 3-65 of the X-15.

The X-15 was a critical research vehicle in the early days of space flight. On November 15, 1967, the X-15-3 suffered an in-flight breakup. It was the 191st flight of the X-15 and the 65th flight of this third configuration (X-15-3). It was the only fatal accident of the X-15 program. This paper presents an analysis, from a human factors perspective, of the events that led up to the accident. The analysis is based on the information contained in the report of the Air Force-NASA Accident Investigation Board (AIB) dated January 1968. Although the X-15 accident occurred in 1967, the results of the presented analysis are as relevant today as they were 47 years ago. We present the main points of our analysis and discuss their implications for the safety of space operations.