Jürgen Sauer
juergen.sauer@unifr.ch
+41 26 300 7622
https://orcid.org/0000-0003-2105-1694
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Ordentliche_r Professor_in,
Departement für Psychologie
RM 01 bu. C-1.117
Rue P.A. de Faucigny 2
1700 Fribourg
Forschung und Publikationen
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Peer-reviewed articles
120 Publikationen
Effects of false alarms and miscues of decision support systems on human–machine system performance: a study with airport security screeners
David Huegli, Alain Chavaillaz, Juergen Sauer, Adrian Schwaninger, Ergonomics (2025) | Artikel -
Forschungsprojekte
Improving work design for airport security officers
Status: AbgeschlossenBeginn 01.11.2019 Ende 31.10.2024 Finanzierung SNF Projektblatt öffnen Screening passenger baggage at airports represents a demanding task with critical implications for aviation security due to the current geopolitical situation (e.g. terrorist threats). While previous research on airport security has focussed on human-machine interaction, visual search and training, less is known about the impact of work design on visual inspection performance. The main goal of this project is to examine work design in the domain of visual inspection aiming to increase performance and decrease workload. As a complementary research goal, the project aims to develop several pictorial scales (as an alternative to verbal scales) that measure subjective states (e.g. workload, fatigue) since such scales may provide several benefits (e.g. more intuitive comprehension, increased respondent motivation, language independence). This project focuses on baggage screening at airports, but the results are also expected to be relevant to other domains of visual search and inspection (e.g. medical imaging, quality control in manufacturing). Work from a preceding SNSF-project showed the need for well-designed workplaces in baggage screening. Work design differs considerably between airports (e.g. local and remote baggage screening), but there is little empirical work from the domain of baggage screening that provides guidance for choosing between different work design options. The current project focuses on three aspects: work schedules, time-related stressors and system design. Regarding work schedules, we will examine the impact of different regimes of rest breaks and night work. The time-related stressors at security checkpoints are notably unscheduled interruptions and time pressure (e.g. due to long passenger queues). System design is concerned with human-machine interaction by examining various design features of current X-ray machines (i.e. diagnostic aids, background colours). Since diagnostic aids pointing out threat items (e.g. explosives) are generally supportive but not perfectly reliable, there is some concern that they impair screener performance by giving miscues (i.e. aid designates a non-threat object but fails to identify a threat item within the same piece of baggage). Further pertinent system-related features are background colours of X-ray images, which are expected to have some bearing on airport security since they influence screener performance and subjective outcome measures such as fatigue and workload. We also envisage the development of pictorial scales to measure psychological constructs such as workload, trust, self-confidence and fatigue. Building on the successful development of two pictorial scales measuring usability, we will use the planned experimental work for testing and validating these four pictorial scales against well-established verbal scales (e.g. NASA-TLX). Since screeners have good skills in interpreting visual stimuli, the use of pictorial items rather than verbal ones may be particularly useful in their domain. We also expect pictorial scales to be valuable in baggage screening given that they would facilitate comparisons between screeners from multilingual countries such as Switzerland. The development of these scales requires their validation in empirical studies, for which the experiments of the present project are very well suited. The project is expected to provide several benefits. First, an existing simulation (LIS: luggage inspection simulation) will be enhanced to model two work environments of airport security officers (local and remote screening). LIS will be made available to the research community. Second, recommendations will be made about how work design for airport security officers could be improved, which is expected to increase airport security. Third, several pictorial scales will be developed and made available to the research community, allowing a non-verbal measurement of important constructs in work psychology. Social stress, social support and performance in human-machine teams
Status: AbgeschlossenBeginn 01.04.2018 Ende 31.05.2023 Finanzierung SNF Projektblatt öffnen The project aims to examine problems associated with social stressors in hybrid teams (i.e. comprising humans and highly automated technical systems) and whether social support can alleviate any negative effects. Whereas no such work has been carried out in hybrid teams, there is ample empirical work on different kinds of social stressors (e.g. bullying, interpersonal conflict) in teams comprising only humans. This work has shown a strong propensity towards field research for most stressors and is also characterised by a shortage of studies taking measurements of performance. To complement this research, a laboratory-based approach is adopted by using a computer-based simulation of a complex technical work environment, which allows measuring multiple performance indicators. The following three work-related social stressors are examined: assignment of illegitimate tasks (i.e. tasks that violate norms with regard to what can be reasonably expected from a job holder) ostracism (i.e. people being excluded and ignored at work) and negative performance feedback in performance appraisal. The three social stressors will be examined in hybrid teams, combined with the provision of social support as an antagonist to the social stressor. The focus on hybrid teams represents a novel approach and allows us to determine whether the outcomes of social stress are fundamentally different depending on whether the social stressor is induced by a human or a machine. Three experiments will examine the effects of these social stressors on performance and on other pertinent outcome measures (e.g. subjective strain, affect). Experiment I investigates the impact of illegitimate task assignment by a human or by a machine agent. Experiment II is concerned with ostracism at work, comparing the effects of being socially excluded by a human colleague or by a machine agent. Experiment III examines the effects of receiving negative performance feedback (from a human or machine agent). Each experiment also aims to determine whether social support is effective in reducing the negative effects of social stress. The methodological approach adopted allows us to measure a broad range of outcome variables, notably objective parameters such as multiple-task performance, information sampling behaviour and psychophysiological data. The work planned is expected to provide several benefits. First, we will gain a better understanding of the extent to which social stress and how social support affects outcome measures that have not yet been examined in previous research (notably objective performance). Second, we will increase our knowledge of how these social processes differ in hybrid team from those in traditional human teams. Third, the work will make a simulation environment available to the research community that allows us to examine social stressors in a laboratory. Designing automation for visual inspection tasks: influence of support system properties and work design factors
Status: AbgeschlossenBeginn 01.03.2014 Ende 31.08.2018 Finanzierung SNF Projektblatt öffnen The present project is concerned with the design of automation to support operators in visual inspection tasks. While these issues have attracted increasing interest in psychological research (notably in quality control in manufacturing, medical diagnoses, and airport security), the potential benefits of automation in visual inspection may not have been fully reaped. The proposed project relates to two preceding SNSF-projects which examined the effectiveness of different forms of automation in the application of process control. It would allow us to determine to what extent the findings gained in highly complex multiple-task environment are transferable to the domain of visual inspection, which is characterised by a single task with considerable mental demands. The present project pursues two main goals. First, it aims to examine whether modern concepts of automation design (e.g., adaptable automation) can also be introduced to a domain requiring high levels of vigilance, like luggage screening, and to determine whether they are of similar benefit in that domain as they have been in others. Second, it aims to examine the implications of introducing higher levels of automation for other work design factors in visual inspection, such as training and rest breaks. These factors are an integral part of the overall socio-technical system and their impact need to be tested in multi-factorial experimental designs. Prior to the completion of the empirical work, a simulation will be developed to model the work environment of luggage screening officers. This simulation environment will be able to model different automation modes (e.g. no automatic support, system informs about presence of target, system indicates location of target) and will be suitable for use in lab-based work as well as in field research. Five experiments are envisaged to examine the effects of providing different forms of automatic support to the operator, in combination with pertinent work design issues surrounding visual inspection tasks (e.g. rest break, training). Experiment 1 is concerned with the effectiveness of adaptable automation (i.e. operators are free to select their preferred level of automation and change it at any time) compared to the more conventional form of static automation (i.e. level of automation is predetermined by the system). Experiments 2 and 3 examine the effects of changing target detection algorithms (e.g., increasing its sensitivity) under different levels of system reliability but also examining the potential of training the operator on automation characteristics. Experiments 4 and 5 adopt a broader perspective by including other important aspects of work design for airport security, such as work/rest schedules and expertise. While a central outcome variable of the research refers to operator performance (notably accuracy and speed in target detection), the measurement of eye movements will provide data about the operators’ visual search behaviour as an important complementary measure. Further measures include automation reliance, trust in automation, and subjective workload. The planned work is expected to provide a number of benefits. First, a task environment will be developed which can be used for lab-based work to model the technical work environment of luggage screening officers. The task environment will be made available to the research community. Second, the findings are expected to contribute to the design of support systems in the context of airport security and other visual inspection tasks. Increasing the effectiveness of usability testing: the role of testing method, cultural background and system features beyond usability
Status: AbgeschlossenBeginn 01.07.2012 Ende 31.12.2016 Finanzierung SNF Projektblatt öffnen Extending the work of a preceding SNSF-project, the current project proposal focuses on the question of how the utility of usability tests can further be improved. While there is little doubt that usability testing is an effective product evaluation method, researchers and practitioners have identified a number of factors surrounding the testing context, which may have an undesirable impact on test outcomes and hence impair the effectiveness of usability tests. Therefore, these contextual factors are to be empirically examined and the degree of their influence is to be determined. The present research project is guided by the Four-Factor Framework of Contextual Fidelity, which proposes a number of aspects that are suspected to have such an undue influence on test outcomes. The proposed project comprises a total of eight experiments, focusing on three main areas. The first area (3 experiments) is concerned with methodological issues of usability testing. This work addresses the impact of using traditional testing approaches (e.g., lab-based testing and single-session testing) on usability test outcomes by comparing these with the more realistic testing conditions of field-based testing and of longitudinal approaches involving multi-session testing. Furthermore, this work includes the empirical evaluation of remote testing as a methodological approach adopted more recently in usability testing. The second area (2 experiments) addresses the influence of cultural background on the outcomes of usability tests. Given that many products are developed for international markets, there is an increasing need to better understand the implications of carrying out usability tests in different cultures. A systematic empirical evaluation of usability test outcomes across several cultures will provide evidence for the influence of intercultural differences. The third area (3 experiments) is concerned with the influence of product features that are unrelated to product usability but still appear to have an influence on perceived usability and sometimes even on objective measures of usability. Examples of such product characteristics include product brand but also visual and non-visual aesthetic features. The proposed project is expected to create benefits at several levels. First, it will provide practitioners with recommendations about important issues to be considered during usability testing, notably concerning the utility of various methodological approaches. Second, the research community will benefit from the empirical data generated by the planned experiments since it allows a more precise assessment of the degree of influence of each of the factors being examined. Effectiveness of explicit and implicit adaptive automation under different work stressors
Status: AbgeschlossenBeginn 01.09.2011 Ende 29.02.2016 Finanzierung SNF Projektblatt öffnen Effectiveness of explicit and implicit adaptive automation under different work stressors Human centered design and evaluation
Status: AbgeschlossenThe utility of usability tests: An examination of factors that influence test outcomes
Status: AbgeschlossenBeginn 01.12.2008 Ende 29.02.2012 Finanzierung SNF Projektblatt öffnen The present project is concerned with the utility of usability tests and how their effectiveness can be improved. While usability tests are undoubtedly helpful in identifying weaknesses in product design, there is little systematic research work examining factors that influence test outcomes. A better understanding of the influence of these factors would allow us to increase the effectiveness of usability tests. There are a number of factors that may impair the reliability and validity of usability tests, ranging from the presence of test observers to the kind of prototype being used. We have developed a model, termed the Four-Factor Framework of Contextual Fidelity, to determine the extent to which the outcomes of usability tests are influenced by various elements of the testing situation. This Four-Factor Framework of Contextual Fidelity guides the proposed research programme, which comprises a series of experiments that evaluate the influence of the four general factors (user, environment, task, technical system). Of particular interest are the elements prototype fidelity, product aesthetics and observer presence for the outcome of usability tests. The research is carried out with typical interactive consumer products (e.g., mobile phone, digital camera), including replications of test scenarios with a product to determine the generalisability of the findings. Furthermore, we plan to compare the pattern of effects for summative and formative evaluation. Finally, we will examine the transferability of the findings from the domain of consumer products to a work context. The findings of the research project will provide guidance to designers and usability practitioners about issues to be considered when conducting usability tests. Adaptive automation and operator state in complex work environments
Status: AbgeschlossenBeginn 01.01.2008 Ende 30.06.2011 Finanzierung SNF Projektblatt öffnen The project proposal aims to examine the needs for designing adaptive automation for use under different operational conditions, such as environmental stressors (e.g., noise) as well as task-related stressors (e.g., emergencies). There is hardly any work in the research literature that has addressed the implications of operator stress for the design of adaptive automation. It is planned to look at automation issues with regard to static functional allocation and different forms of dynamic allocation of function, such as explicit, event-based and performance-based allocation. The methodological approach broadly follows the micro-world research paradigm, with a computerbased simulation being employed to model the work environment of an operator of a process control system. Two experiments will be conducted to examine the combined effects of adaptive automation and operator stress. The first experiment aims to compare the impact of two forms of static automation (low vs. high level of automation) with explicit dynamic allocation of function under changing operational conditions (i.e. various degrees of environmental and task-related stress). The goal of the second experiment is to examine the impact of explicit dynamic allocation of function and two forms of implicit adaptive automation (event-based and performance-based), again under different environmental and task-related stressors. In both experiments, a wide range of measures are taken, such as primary and secondary task performance, information sampling and system control behaviour, subjective operator state and physiological parameters. This allows the capture of the multi-facetted human adaptation processes that are to be expected under these varying demands modelled by the different experimental conditions. A major benefit of the project is the development of recommendations for the design of adaptive automation systems that are robust against variations in environmental and task-related stress. This represents an endeavour to achieve a stronger integration of the fields of cognitive engineering and stress research. Finally, an existing computer-based simulation environment will be enhanced for testing various options of designing adaptive automation. This tool will be made available to the research community. Training in process control: Supporting performance in consideration of operator characteristics
Status: Abgeschlossen