Franziska Hofer - Academia.edu (original) (raw)

Papers by Franziska Hofer

WIT Transactions on the Built Environment, May 25, 2005

Threat image projection (TIP) is a technology of current x-ray machines that allows exposing scre... more Threat image projection (TIP) is a technology of current x-ray machines that allows exposing screeners to artificial but realistic x-ray images during the routine baggage x-ray screening operation. If a screener does not detect a TIP within a specified amount of time, a feedback message appears indicating that a projected image was missed. Feedback messages are also shown when a TIP image is detected or in the case of a non-TIP alarm, i.e. when the screener indicated that there was a threat but in fact no TIP was shown. TIP data is an interesting source for quality control, risk analysis and the assessment of individual screener performance. In two studies we examined the conditions for using TIP data for the latter purpose. Our results strongly suggest using aggregated data in order to have a large enough data sample as the basis for statistical analysis. Second, an appropriate TIP library containing a large number of threat items, which are representative for the prohibited items to be detected, is recommended. Furthermore, consideration should be given to image-based factors such as general threat item difficulty, viewpoint difficulty, superposition and bag complexity. Different methods to cope with these issues are discussed in order to achieve reliable, valid and standardized measurements of individual screener performance using TIP.

Journal of Transportation Security, Nov 25, 2021

Selective security screenings are discussed as a potential strategy to reduce costs and waiting t... more Selective security screenings are discussed as a potential strategy to reduce costs and waiting times at airports, while keeping security high. However, the limited literature suggests that traditional security screenings, where all passengers are screened, are perceived as more deterrent for criminal activity and more secure from passengers' perspectives. The goal of this study was to investigate whether targeted communication on an airport's website can counteract the detrimental effect of randomised airport security checks on deterrence. The study results confirm prior findings that people with illegal intentions prefer randomised security checks compared to traditional security checks. However, there are hints that tactical communication could be a tool to improve security at airports. All in all, the insights gathered in this study should be taken as a sign of caution, when considering switching to selective security screenings. Future directions for investigating the effect of tactical communication are discussed.

The impact of leadership structure and behavior on team or crew performance is well known and has... more The impact of leadership structure and behavior on team or crew performance is well known and has been demonstrated in various studies (see e.g. Guzzo & Dickson, 1996; Zaccaro, Rittmann, & Marks, 2001). However, as far as we know, there is no empirical study available on leadership structures and crew performance in the applied setting of airport security control. This study compares the structure and impact of two different leadership models for security control. The first (older) model consists of one supervisor per sector. In the supervisor's sector, there are three to eight crews at work, each consisting of five security officers (SOs). Each crew independently manages and operates one line of the checkpoint. One of the five SOs in a crew is the crew leader (CL), who works together with the crew as a normal crew member but has a few additional tasks to fulfill. The second (newer) model, which focuses more on integrated crew resource management (CRM) criteria, consists of one supervisor, assisted by two CLs per sector. Together, they form a cohesive leading team. The CLs do not work in the crews anymore but manage two to three lines from behind. The crews still consist of five SOs. It is the new CLs' task to quickly isolate and manage problematic cases so that those do not block the line anymore. Like this, the workload of each team member is reduced. Another task is to keep an eye on the working quality and to communicate with the crews in such a way that working quality is enhanced. The impact of this reinforced leadership on indicators of working quality such as compliance with rules and regulations, as well as its impact on passenger flow (throughput) are analyzed using different statistical procedures such as T-tests, U-tests and Chi-square tests. Moreover, the job models of the new leadership structure are presented in detail and SOs' ratings of their acceptance and liking of both systems are presented. In sum, this study offers another, different approach to the human factors perspective in airport security focusing on leadership structures, crew resource management, and their effects.

Behavior Research Methods

The response time-based Concealed Information Test (RT-CIT) is an established memory detection pa... more The response time-based Concealed Information Test (RT-CIT) is an established memory detection paradigm. Slower RTs to critical information (called ‘probes’) compared to control items (called ‘irrelevants’) reveal recognition. Different lines of research indicate that response conflict is a strong contributor to this RT difference. Previous studies used electromyography (EMG) to measure response conflict, but this requires special equipment and trained examiners. The aim of this study was to explore if response conflict can also be measured with an analog gaming keyboard that is sensitive to minimal finger movements. In a preregistered study, participants completed an autobiographical RT-CIT (n = 35) as well as a cued recognition task (modified Sternberg task; n = 33) for validation purposes. Partial errors, partial button presses of the incorrect response key, were more frequent in trials with response conflict than in trials without conflict. Partial errors were rare (CIT: 2.9%; S...

X-ray screening is a demanding task. Threat objects can be superimposed by other objects, they ca... more X-ray screening is a demanding task. Threat objects can be superimposed by other objects, they can be difficult to recognize in cluttered bags, or when depicted from an unusual viewpoint. For improving airport security screening, it is essential to develop tests for pre-employment assessment in order to identify those people who are well-suited for the x-ray screening task. The X-Ray Object Recognition Test (X-Ray ORT) has been developed to measure how well people can cope with x-ray images in which threat items are superimposed by other objects, placed in cluttered bags, or depicted from unusual viewpoints. In this study, the X-Ray ORT was used in pre-employment assessment to select the 50 percent best performing candidates. These candidates(n=101) were then tested one year later using a standardized x-ray image interpretation test containing different types of prohibited items (X-Ray PIT). Detection performance of these screeners was significantly better than the performance of the other screening personnel (n = 453), that was not selected based on the X-Ray ORT. Additional analyses showed good reliability and validity of this test, indicating that the X-Ray ORT is a very useful tool for pre-employment assessment in order to increase the x-ray screening performance.

Natural scenes constitute a very heterogeneous stimulus class. Each semantic category contains ex... more Natural scenes constitute a very heterogeneous stimulus class. Each semantic category contains exemplars of varying typicality. It is, therefore, an interesting question whether humans can categorize natural scenes consistently into a relatively small number of categories, such as, coasts, rivers/lakes, forests, plains, and mountains. This is particularly important for applications, such as, image retrieval systems. Only if typicality is consistently perceived across different individuals, a general image-retrieval system makes sense. In this study, we use psychophysics and computational modeling to gain a deeper understanding of scene typicality. In the first psychophysical experiment, we used a forced-choice categorization task in which each of 250 natural scenes had to be classified into one of the following five categories: coasts, rivers/lakes, forests, plains, and mountains. In the second experiment, the typicality of each scene had to be rated on a 50-point scale for each of ...

Journal of Transportation Security, 2021

Selective security screenings are discussed as a potential strategy to reduce costs and waiting t... more Selective security screenings are discussed as a potential strategy to reduce costs and waiting times at airports, while keeping security high. However, the limited literature suggests that traditional security screenings, where all passengers are screened, are perceived as more deterrent for criminal activity and more secure from passengers’ perspectives. The goal of this study was to investigate whether targeted communication on an airport’s website can counteract the detrimental effect of randomised airport security checks on deterrence. The study results confirm prior findings that people with illegal intentions prefer randomised security checks compared to traditional security checks. However, there are hints that tactical communication could be a tool to improve security at airports. All in all, the insights gathered in this study should be taken as a sign of caution, when considering switching to selective security screenings. Future directions for investigating the effect of...

The reaction time-based Concealed Information Test (RT-CIT) has been used to judge the veracity o... more The reaction time-based Concealed Information Test (RT-CIT) has been used to judge the veracity of an examinees claim to be naïve about an incident by testing his/her memory of relevant details. Here, we explore the validity of the RT-CIT to generate new knowledge about the incident – the searching CIT. In a mock terrorism study (n = 60) the searching RT-CIT allowed to detect crime information well above chance, with sampling error possibly underestimating its true potential. A simulation study confirms the potential of the searching RT-CIT, and identifies conditions under which it best performs. We used an archival data-set that met these conditions (high CIT effect, large number of item repetitions), and found better item classification performance than in the mock terrorism study. Although the classification is far from perfect, the searching RT-CIT could be a new, promising investigative tool to reveal new crime details to the investigative party.

WIT Transactions on The Built Environment, 2005

Threat image projection (TIP) is a technology of current x-ray machines that allows exposing scre... more Threat image projection (TIP) is a technology of current x-ray machines that allows exposing screeners to artificial but realistic x-ray images during the routine baggage x-ray screening operation. If a screener does not detect a TIP within a specified amount of time, a feedback message appears indicating that a projected image was missed. Feedback messages are also shown when a TIP image is detected or in the case of a non-TIP alarm, i.e. when the screener indicated that there was a threat but in fact no TIP was shown. TIP data is an interesting source for quality control, risk analysis and the assessment of individual screener performance. In two studies we examined the conditions for using TIP data for the latter purpose. Our results strongly suggest using aggregated data in order to have a large enough data sample as the basis for statistical analysis. Second, an appropriate TIP library containing a large number of threat items, which are representative for the prohibited items to be detected, is recommended. Furthermore, consideration should be given to image-based factors such as general threat item difficulty, viewpoint difficulty, superposition and bag complexity. Different methods to cope with these issues are discussed in order to achieve reliable, valid and standardized measurements of individual screener performance using TIP.

R&D Management, 2016

Intellectual property infringements rank among the top economic crimes, even though there are mec... more Intellectual property infringements rank among the top economic crimes, even though there are mechanisms in place to prevent their occurrence. One such mechanism are nondisclosure agreements, which, however, have been reported to fail in practice. This article argues that this may be overcome by strengthening employees' concept learning. In an experiment, we investigated whether extended nondisclosure agreements, which provide the employee with detailed explanations and examples, lead to better recognition of trade secrets as compared to a standard nondisclosure agreement or no agreement at all. It was found that the extended nondisclosure agreement indeed increased participants' ability to judge what falls under the trade secret law, whereas the standard nondisclosure agreement showed no such effect. Furthermore, the effects of the factors 'Involvement', 'Specificity', 'Publicity', and 'Purpose' on the identification of trade secrets could be proven experimentally. Employees' judgments of whether an information represents a trade secret seem to rely on general cognitive processes. From this follows that concept learning could be integrated into systematic approaches for protecting intellectual property.

2011 Carnahan Conference on Security Technology, 2011

Ensuring smooth operation of an airport is a complex task with many stakeholders involved that ha... more Ensuring smooth operation of an airport is a complex task with many stakeholders involved that have to work together closely in order to achieve optimal results. In particular, the field of security control harbors diverging interests of different entities that share responsibility for secure and timely flights. These entities usually comprise governmental organizations (e.g., legislative authorities, police) and private companies (e.g., airport operators, private security companies). Due to conflicting interests between these entities, managers might perceive each other as adversaries rather than as partners for collaboration. To our knowledge, the present report is the first one to relate procedure and results of a fruitful collaboration on management level between representatives of these different entities at an airport, including a governmental organization as the executive, i.e., carrying out the security control, and a private company (the airport operator). In the setting of the security control at a large European airport, the Productivity Measurement and Enhancement System (ProMES) methodology [1] was chosen to identify stakeholders in the security control process as a first step in order to be able to define their interests, demands, and needs in a second step. Subsequently, justified demands were grouped and categorized into six goal domains. For each goal domain, key performance indicators were developed. Last but not least, the indicators were prioritized by weighing their relevance against each other in order to resolve conflicting interests. This process can be rather quick and efficient provided it is well prepared and monitored. It is further suggested to have an independent facilitator supervise and moderate the process. This study highlights the importance of bringing together high level managers of different organizational entities with a systematical approach in order to pave the way for good cooperation in complex work domains. As a result, stakeholders and demands can be identified, conflicting demands can be discussed, and priorities set. Subsequently, those guidelines can be handed over to the next lower level in the organizational hierarchy. Supervisors on this next level can then define goals for their respective domains using the guidelines provided by the management.

38th Annual 2004 International Carnahan Conference on Security Technology, 2004.

Over the last decades, airport security technology has evolved remarkably. This is especially evi... more Over the last decades, airport security technology has evolved remarkably. This is especially evident when state-of-the-art detection systems are concerned. However, such systems are only as effective as the personnel who operate them. Reliable and valid measures of screener detection performance are important for risk analysis, screener certification and competency assessment, as well as for measuring quality performance and effectiveness of training systems. In many of these applications the hit rate is used in order to measure detection performance. However, measures based on signal detection theory have gained popularity in recent years, for example in the analysis of data from threat image projection (TIP) or computer based training (CBT) systems. In this study, computer-based tests were used to measure detection performance for improvised explosive devices (IEDs). These tests were conducted before and after training with an individually adaptive CBT system. The following measures were calculated: pHit, d', ∆m, Az, A', p(c) max. All measures correlated well, but ROC curve analysis suggests that "nonparametric" measures are more valid to measure detection performance for IEDs. More specifically, we found systematic deviations in the ROC curves that are consistent with two-state low threshold theory of [9]. These results have to be further studied and the question rises if similar results could be obtained for other X-ray screening data. In any case, it is recommended to use A' in addition to d' in practical applications such as certification, threat image projection and CBT rather than the hit rate alone. Index Terms-human factors in aviation security, hit rate, signal detection theory, threat detection in X-ray screening, computer based training system, threat image projection.

38th Annual 2004 International Carnahan Conference on Security Technology, 2004.

A central aspect of airport security is reliable detection of forbidden objects in passenger bags... more A central aspect of airport security is reliable detection of forbidden objects in passenger bags using Xray screening equipment. Human recognition involves visual processing of the X-ray image and matching items with object representations stored in visual memory. Thus, without knowing which objects are forbidden and what they look like, prohibited items are difficult to recognize (aspect of visual knowledge). In order to measure whether a screener has acquired the necessary visual knowledge, we have applied the prohibited items test (PIT). This test contains different forbidden items according to international prohibited items lists. The items are placed in X-ray images of passenger bags so that the object shapes can be seen relatively well. Since all images can be inspected for 10 seconds, failing to recognize a threat item can be mainly attributed to a lack of visual knowledge. The object recognition test (ORT) is more related to visual processing and encoding. Three image-based factors can be distinguished that challenge different visual processing abilities. First, depending on the rotation within a bag, an object can be more or less difficult to recognize (effect of viewpoint). Second, prohibited items can be more or less superimposed by other objects, which can impair detection performance (effect of superposition). Third, the number and type of other objects in a bag can challenge visual search and processing capacity (effect of bag complexity). The ORT has been developed to measure how well screeners can cope with these image-based factors. This test contains only guns and knives, placed into bags in different views with different superposition and complexity levels. Detection performance is determined by the ability of a screener to detect threat items despite rotation, superposition and bag complexity. Since the shapes of guns and knives are usually known well even by novices, the aspect of visual threat object knowledge is of minor importance in this test.

Journal of Air Transport Management

Journal of Transportation Security, 2012

The history of airport security shows that the security control process has been subject to subst... more The history of airport security shows that the security control process has been subject to substantial changes since its introduction in the early seventies of the last century. In the course of time, threat profiles have changed remarkably. Since 2001, suicide bombing has become a real risk to civil aviation. In the last decade, these changes in threat profiles, in combination with efforts to facilitate transportation by air for passengers, led to large investments into the development of new security technology. This article argues that during the development of security technology, human factor issues as well as different operational aspects should be taken into account at an early stage. It is shown how early operational testing of new technology can contribute to the optimization of security equipment and its integration into the system from a human factors perspective. Operational testing complements laboratory testing and is defined as the testing of (new) equipment in operation with a focus on systemic performance outcomes and operational aspects. Using this methodological approach, a millimeter-wave body scanner and two different liquid explosives detection systems were tested in operation with passengers at a large European airport. Results were obtained by analyzing objective data as well as subjective questionnaire data from passengers and Security Officers. These trials revealed that operational testing is a useful way of enhancing shared knowledge and collaboration between stakeholders.

WIT Transactions on the Built Environment, May 25, 2005

Threat image projection (TIP) is a technology of current x-ray machines that allows exposing scre... more Threat image projection (TIP) is a technology of current x-ray machines that allows exposing screeners to artificial but realistic x-ray images during the routine baggage x-ray screening operation. If a screener does not detect a TIP within a specified amount of time, a feedback message appears indicating that a projected image was missed. Feedback messages are also shown when a TIP image is detected or in the case of a non-TIP alarm, i.e. when the screener indicated that there was a threat but in fact no TIP was shown. TIP data is an interesting source for quality control, risk analysis and the assessment of individual screener performance. In two studies we examined the conditions for using TIP data for the latter purpose. Our results strongly suggest using aggregated data in order to have a large enough data sample as the basis for statistical analysis. Second, an appropriate TIP library containing a large number of threat items, which are representative for the prohibited items to be detected, is recommended. Furthermore, consideration should be given to image-based factors such as general threat item difficulty, viewpoint difficulty, superposition and bag complexity. Different methods to cope with these issues are discussed in order to achieve reliable, valid and standardized measurements of individual screener performance using TIP.

Journal of Transportation Security, Nov 25, 2021

Selective security screenings are discussed as a potential strategy to reduce costs and waiting t... more Selective security screenings are discussed as a potential strategy to reduce costs and waiting times at airports, while keeping security high. However, the limited literature suggests that traditional security screenings, where all passengers are screened, are perceived as more deterrent for criminal activity and more secure from passengers' perspectives. The goal of this study was to investigate whether targeted communication on an airport's website can counteract the detrimental effect of randomised airport security checks on deterrence. The study results confirm prior findings that people with illegal intentions prefer randomised security checks compared to traditional security checks. However, there are hints that tactical communication could be a tool to improve security at airports. All in all, the insights gathered in this study should be taken as a sign of caution, when considering switching to selective security screenings. Future directions for investigating the effect of tactical communication are discussed.

The impact of leadership structure and behavior on team or crew performance is well known and has... more The impact of leadership structure and behavior on team or crew performance is well known and has been demonstrated in various studies (see e.g. Guzzo & Dickson, 1996; Zaccaro, Rittmann, & Marks, 2001). However, as far as we know, there is no empirical study available on leadership structures and crew performance in the applied setting of airport security control. This study compares the structure and impact of two different leadership models for security control. The first (older) model consists of one supervisor per sector. In the supervisor's sector, there are three to eight crews at work, each consisting of five security officers (SOs). Each crew independently manages and operates one line of the checkpoint. One of the five SOs in a crew is the crew leader (CL), who works together with the crew as a normal crew member but has a few additional tasks to fulfill. The second (newer) model, which focuses more on integrated crew resource management (CRM) criteria, consists of one supervisor, assisted by two CLs per sector. Together, they form a cohesive leading team. The CLs do not work in the crews anymore but manage two to three lines from behind. The crews still consist of five SOs. It is the new CLs' task to quickly isolate and manage problematic cases so that those do not block the line anymore. Like this, the workload of each team member is reduced. Another task is to keep an eye on the working quality and to communicate with the crews in such a way that working quality is enhanced. The impact of this reinforced leadership on indicators of working quality such as compliance with rules and regulations, as well as its impact on passenger flow (throughput) are analyzed using different statistical procedures such as T-tests, U-tests and Chi-square tests. Moreover, the job models of the new leadership structure are presented in detail and SOs' ratings of their acceptance and liking of both systems are presented. In sum, this study offers another, different approach to the human factors perspective in airport security focusing on leadership structures, crew resource management, and their effects.

Behavior Research Methods

The response time-based Concealed Information Test (RT-CIT) is an established memory detection pa... more The response time-based Concealed Information Test (RT-CIT) is an established memory detection paradigm. Slower RTs to critical information (called ‘probes’) compared to control items (called ‘irrelevants’) reveal recognition. Different lines of research indicate that response conflict is a strong contributor to this RT difference. Previous studies used electromyography (EMG) to measure response conflict, but this requires special equipment and trained examiners. The aim of this study was to explore if response conflict can also be measured with an analog gaming keyboard that is sensitive to minimal finger movements. In a preregistered study, participants completed an autobiographical RT-CIT (n = 35) as well as a cued recognition task (modified Sternberg task; n = 33) for validation purposes. Partial errors, partial button presses of the incorrect response key, were more frequent in trials with response conflict than in trials without conflict. Partial errors were rare (CIT: 2.9%; S...

X-ray screening is a demanding task. Threat objects can be superimposed by other objects, they ca... more X-ray screening is a demanding task. Threat objects can be superimposed by other objects, they can be difficult to recognize in cluttered bags, or when depicted from an unusual viewpoint. For improving airport security screening, it is essential to develop tests for pre-employment assessment in order to identify those people who are well-suited for the x-ray screening task. The X-Ray Object Recognition Test (X-Ray ORT) has been developed to measure how well people can cope with x-ray images in which threat items are superimposed by other objects, placed in cluttered bags, or depicted from unusual viewpoints. In this study, the X-Ray ORT was used in pre-employment assessment to select the 50 percent best performing candidates. These candidates(n=101) were then tested one year later using a standardized x-ray image interpretation test containing different types of prohibited items (X-Ray PIT). Detection performance of these screeners was significantly better than the performance of the other screening personnel (n = 453), that was not selected based on the X-Ray ORT. Additional analyses showed good reliability and validity of this test, indicating that the X-Ray ORT is a very useful tool for pre-employment assessment in order to increase the x-ray screening performance.

Natural scenes constitute a very heterogeneous stimulus class. Each semantic category contains ex... more Natural scenes constitute a very heterogeneous stimulus class. Each semantic category contains exemplars of varying typicality. It is, therefore, an interesting question whether humans can categorize natural scenes consistently into a relatively small number of categories, such as, coasts, rivers/lakes, forests, plains, and mountains. This is particularly important for applications, such as, image retrieval systems. Only if typicality is consistently perceived across different individuals, a general image-retrieval system makes sense. In this study, we use psychophysics and computational modeling to gain a deeper understanding of scene typicality. In the first psychophysical experiment, we used a forced-choice categorization task in which each of 250 natural scenes had to be classified into one of the following five categories: coasts, rivers/lakes, forests, plains, and mountains. In the second experiment, the typicality of each scene had to be rated on a 50-point scale for each of ...

Journal of Transportation Security, 2021

Selective security screenings are discussed as a potential strategy to reduce costs and waiting t... more Selective security screenings are discussed as a potential strategy to reduce costs and waiting times at airports, while keeping security high. However, the limited literature suggests that traditional security screenings, where all passengers are screened, are perceived as more deterrent for criminal activity and more secure from passengers’ perspectives. The goal of this study was to investigate whether targeted communication on an airport’s website can counteract the detrimental effect of randomised airport security checks on deterrence. The study results confirm prior findings that people with illegal intentions prefer randomised security checks compared to traditional security checks. However, there are hints that tactical communication could be a tool to improve security at airports. All in all, the insights gathered in this study should be taken as a sign of caution, when considering switching to selective security screenings. Future directions for investigating the effect of...

The reaction time-based Concealed Information Test (RT-CIT) has been used to judge the veracity o... more The reaction time-based Concealed Information Test (RT-CIT) has been used to judge the veracity of an examinees claim to be naïve about an incident by testing his/her memory of relevant details. Here, we explore the validity of the RT-CIT to generate new knowledge about the incident – the searching CIT. In a mock terrorism study (n = 60) the searching RT-CIT allowed to detect crime information well above chance, with sampling error possibly underestimating its true potential. A simulation study confirms the potential of the searching RT-CIT, and identifies conditions under which it best performs. We used an archival data-set that met these conditions (high CIT effect, large number of item repetitions), and found better item classification performance than in the mock terrorism study. Although the classification is far from perfect, the searching RT-CIT could be a new, promising investigative tool to reveal new crime details to the investigative party.

WIT Transactions on The Built Environment, 2005

Threat image projection (TIP) is a technology of current x-ray machines that allows exposing scre... more Threat image projection (TIP) is a technology of current x-ray machines that allows exposing screeners to artificial but realistic x-ray images during the routine baggage x-ray screening operation. If a screener does not detect a TIP within a specified amount of time, a feedback message appears indicating that a projected image was missed. Feedback messages are also shown when a TIP image is detected or in the case of a non-TIP alarm, i.e. when the screener indicated that there was a threat but in fact no TIP was shown. TIP data is an interesting source for quality control, risk analysis and the assessment of individual screener performance. In two studies we examined the conditions for using TIP data for the latter purpose. Our results strongly suggest using aggregated data in order to have a large enough data sample as the basis for statistical analysis. Second, an appropriate TIP library containing a large number of threat items, which are representative for the prohibited items to be detected, is recommended. Furthermore, consideration should be given to image-based factors such as general threat item difficulty, viewpoint difficulty, superposition and bag complexity. Different methods to cope with these issues are discussed in order to achieve reliable, valid and standardized measurements of individual screener performance using TIP.

R&D Management, 2016

Intellectual property infringements rank among the top economic crimes, even though there are mec... more Intellectual property infringements rank among the top economic crimes, even though there are mechanisms in place to prevent their occurrence. One such mechanism are nondisclosure agreements, which, however, have been reported to fail in practice. This article argues that this may be overcome by strengthening employees' concept learning. In an experiment, we investigated whether extended nondisclosure agreements, which provide the employee with detailed explanations and examples, lead to better recognition of trade secrets as compared to a standard nondisclosure agreement or no agreement at all. It was found that the extended nondisclosure agreement indeed increased participants' ability to judge what falls under the trade secret law, whereas the standard nondisclosure agreement showed no such effect. Furthermore, the effects of the factors 'Involvement', 'Specificity', 'Publicity', and 'Purpose' on the identification of trade secrets could be proven experimentally. Employees' judgments of whether an information represents a trade secret seem to rely on general cognitive processes. From this follows that concept learning could be integrated into systematic approaches for protecting intellectual property.

2011 Carnahan Conference on Security Technology, 2011

Ensuring smooth operation of an airport is a complex task with many stakeholders involved that ha... more Ensuring smooth operation of an airport is a complex task with many stakeholders involved that have to work together closely in order to achieve optimal results. In particular, the field of security control harbors diverging interests of different entities that share responsibility for secure and timely flights. These entities usually comprise governmental organizations (e.g., legislative authorities, police) and private companies (e.g., airport operators, private security companies). Due to conflicting interests between these entities, managers might perceive each other as adversaries rather than as partners for collaboration. To our knowledge, the present report is the first one to relate procedure and results of a fruitful collaboration on management level between representatives of these different entities at an airport, including a governmental organization as the executive, i.e., carrying out the security control, and a private company (the airport operator). In the setting of the security control at a large European airport, the Productivity Measurement and Enhancement System (ProMES) methodology [1] was chosen to identify stakeholders in the security control process as a first step in order to be able to define their interests, demands, and needs in a second step. Subsequently, justified demands were grouped and categorized into six goal domains. For each goal domain, key performance indicators were developed. Last but not least, the indicators were prioritized by weighing their relevance against each other in order to resolve conflicting interests. This process can be rather quick and efficient provided it is well prepared and monitored. It is further suggested to have an independent facilitator supervise and moderate the process. This study highlights the importance of bringing together high level managers of different organizational entities with a systematical approach in order to pave the way for good cooperation in complex work domains. As a result, stakeholders and demands can be identified, conflicting demands can be discussed, and priorities set. Subsequently, those guidelines can be handed over to the next lower level in the organizational hierarchy. Supervisors on this next level can then define goals for their respective domains using the guidelines provided by the management.

38th Annual 2004 International Carnahan Conference on Security Technology, 2004.

Over the last decades, airport security technology has evolved remarkably. This is especially evi... more Over the last decades, airport security technology has evolved remarkably. This is especially evident when state-of-the-art detection systems are concerned. However, such systems are only as effective as the personnel who operate them. Reliable and valid measures of screener detection performance are important for risk analysis, screener certification and competency assessment, as well as for measuring quality performance and effectiveness of training systems. In many of these applications the hit rate is used in order to measure detection performance. However, measures based on signal detection theory have gained popularity in recent years, for example in the analysis of data from threat image projection (TIP) or computer based training (CBT) systems. In this study, computer-based tests were used to measure detection performance for improvised explosive devices (IEDs). These tests were conducted before and after training with an individually adaptive CBT system. The following measures were calculated: pHit, d', ∆m, Az, A', p(c) max. All measures correlated well, but ROC curve analysis suggests that "nonparametric" measures are more valid to measure detection performance for IEDs. More specifically, we found systematic deviations in the ROC curves that are consistent with two-state low threshold theory of [9]. These results have to be further studied and the question rises if similar results could be obtained for other X-ray screening data. In any case, it is recommended to use A' in addition to d' in practical applications such as certification, threat image projection and CBT rather than the hit rate alone. Index Terms-human factors in aviation security, hit rate, signal detection theory, threat detection in X-ray screening, computer based training system, threat image projection.

38th Annual 2004 International Carnahan Conference on Security Technology, 2004.

A central aspect of airport security is reliable detection of forbidden objects in passenger bags... more A central aspect of airport security is reliable detection of forbidden objects in passenger bags using Xray screening equipment. Human recognition involves visual processing of the X-ray image and matching items with object representations stored in visual memory. Thus, without knowing which objects are forbidden and what they look like, prohibited items are difficult to recognize (aspect of visual knowledge). In order to measure whether a screener has acquired the necessary visual knowledge, we have applied the prohibited items test (PIT). This test contains different forbidden items according to international prohibited items lists. The items are placed in X-ray images of passenger bags so that the object shapes can be seen relatively well. Since all images can be inspected for 10 seconds, failing to recognize a threat item can be mainly attributed to a lack of visual knowledge. The object recognition test (ORT) is more related to visual processing and encoding. Three image-based factors can be distinguished that challenge different visual processing abilities. First, depending on the rotation within a bag, an object can be more or less difficult to recognize (effect of viewpoint). Second, prohibited items can be more or less superimposed by other objects, which can impair detection performance (effect of superposition). Third, the number and type of other objects in a bag can challenge visual search and processing capacity (effect of bag complexity). The ORT has been developed to measure how well screeners can cope with these image-based factors. This test contains only guns and knives, placed into bags in different views with different superposition and complexity levels. Detection performance is determined by the ability of a screener to detect threat items despite rotation, superposition and bag complexity. Since the shapes of guns and knives are usually known well even by novices, the aspect of visual threat object knowledge is of minor importance in this test.

Journal of Air Transport Management

Journal of Transportation Security, 2012

The history of airport security shows that the security control process has been subject to subst... more The history of airport security shows that the security control process has been subject to substantial changes since its introduction in the early seventies of the last century. In the course of time, threat profiles have changed remarkably. Since 2001, suicide bombing has become a real risk to civil aviation. In the last decade, these changes in threat profiles, in combination with efforts to facilitate transportation by air for passengers, led to large investments into the development of new security technology. This article argues that during the development of security technology, human factor issues as well as different operational aspects should be taken into account at an early stage. It is shown how early operational testing of new technology can contribute to the optimization of security equipment and its integration into the system from a human factors perspective. Operational testing complements laboratory testing and is defined as the testing of (new) equipment in operation with a focus on systemic performance outcomes and operational aspects. Using this methodological approach, a millimeter-wave body scanner and two different liquid explosives detection systems were tested in operation with passengers at a large European airport. Results were obtained by analyzing objective data as well as subjective questionnaire data from passengers and Security Officers. These trials revealed that operational testing is a useful way of enhancing shared knowledge and collaboration between stakeholders.