LITERATURE REVIEW GIUSEPPE FRAU DEEP BLUE SRL UNIVERSITA’ DI ROMA 3 INTRODUCTION AND PROBLEM STATEMENT 3 LITERATURE REVIEW DESCRIPTION OF AUTOMATION 5 5 INTERACTING WITH AUTOMATION SITUATION AWARENESS FEEDBACK – WARNING – ATTENTION – BOREDOM WORKLOAD 10 10 11 14 INTERACTION TECHNIQUES ENABLER TECHNOLOGIES 16 20 REFERENCES 22 INTRODUCTION AND PROBLEM STATEMENT Overcoming the traditional human-automation issues is a challenge that has been addressed by many research works. Design choices like picking the right level of automation (or deciding for an adaptive automation), or correctly distributing roles and tasks between the human and the system etc. are very important decisions that deserve robust foundations in order to “build the system right”. However, what do we do after we have made those choices? How is the automation affecting the real interaction with the operator and how do we cope with that? Choosing the right level of automation doesn’t guarantee us a sound interaction. Neither the right task allocation does. Failures can happen in the real interactive actions due to poorly designed interfaces. It is necessary to map the system design choices to the more suitable interaction techniques and user-interface design methods. Moreover, in the recent years, we assisted to a growing maturity of several technologies that are enabling and making accessible new means of interaction. We are in the middle of three big innovation trends. A first trend represented by the predictable hardware progress [Moore’s Law and [3]], a second one characterized by “long periods of stability interrupted by rapid changes” [3], and finally the ATM one, involved in the big innovation started with SESAR. Figure 1 - Qualitative representation of HW, User Interfaces and ATM Progresses over time This literature review will put the basis for my research project, which aims to answer the above-mentioned questions What is the automation impact on the real interaction and user interfaces How do we link the system design choices to the suitable interaction techniques How do we take advantage of the new interaction techniques? LITERATURE REVIEW Human Automation Interaction research field has made a wide effort to produce theoretical frameworks and guidelines for the design of highly automated systems. Researchers and designers have been trying to use these results in order to develop effective proof of the actual correctness of the underlying theories. This literature review will go through the main theoretical findings of the automation field and through some of the main practical realizations trying to highlight the gaps between these two words. DESCRIPTION OF AUTOMATION We can identify several dimensions of automation. In [16] for example, O’Hara and Higgings, identified 6 dimensions (applied to the nuclear-power plant cases): levels, functions, processes, modes, flexibility and reliability. However not all of them are applicable in different fields. From the level dimension of automation point of view, the work of Parasuraman [17] it is wildly used as the framework of reference at least in the ATM world. Parasuraman identifies four broad classes of function in which automation can be applied, he highlights how the automation is represented by a continuum of solution from manual control to full automated systems. Figure 2 - Four classes of functions in Parasuraman work The authors also propose a ten levels granularity of automation mainly for the Decision and Action selection stages. Figure 3 - Levels of automation for Decision and Action Selection Two broad sets of criteria are then identified in order to help the designers in the selection of the most suitable levels of automation: human performance is the first criteria while automation reliability and cost of the decision and action consequences represent the second criteria. As the authors state, their model does not claim to provide comprehensive design principles but it can be used in the early stages of the design to get a support about what types and levels of automation implement and what issues the designers are more likely to face as consequences of their choices. Moreover several limitations -in some extent anticipated by the authors- of the practical applicability of this works have been found recently [21]. Save and Feuerberg developed a new level of automation taxonomy after trying to apply the traditional automation frameworks to concrete automation examples. They noticed how the traditional theories are still useful to understand the variable nature of the automation support but sometimes not applicable to the concrete cases basically because specific levels of automation are not specified for each class of function. The authors argue that each class of function (Information Acquisition, Information Analysis, Decision and Selection and Action Implementation) has its own levels of automation and they differ both in the number of levels and in the nature of support. Limitations of this approach can be found in the lost of comparison between the different functions: if each function has its own levels it’s not clear anymore how a level of one function is directly comparable with a level of a different function. The same seminal work of Parasuraman [17] can also represent the base for the function dimension of automation. The classes of functions to which automation can be applied are identified as information acquisition, information analysis, decision and action selection and action implementation. The automated functions are mapped with the cognitive functions of the human being. Similar functions have been identified in the field of Nuclear Power Plants automation. O’Hara [16] for example refers to a set of five functions classified as follow: Monitoring and detection: represents the set of activities used for the information extraction and for establish the status of the plant Situation Assessment: refers to the activities involved in the evaluation of the current condition that is deciding if the status of the system is acceptable and if not, what are the reasons. Response Planning: represents the decisions of what are the actions that are considered suitable to be implemented in the current situation. Response Implementation: refers to the actual execution of the decided actions. Interface Management: refers to the actions required to configure the human machine interface, navigating, arranging informations. The automation mode dimension would deserve a dedicated literature review itself, as there is no commonly accepted precise definition of the word “mode”. Being over simplistic we can use the O’Hara statements “modes involve performing the same functions in different ways. They provide capacity for a system to do different tasks or to accomplish the same task using different strategies under changing conditions”. Vicente and Jamieson [12] provide a sufficient overview of the mode challenges as mode transition design and mode awareness and they offer a set of principles for the automation design facing those issues. Degani [6] defines a mode as “the manner of behaviour of a given system” in which a behaviour is defined by the machine’s input, output, and state as a function of time. In his definition, Degani points out how a mode/behaviour can be imposed either by the machine or by the operator. He classified the modes according to two attributes: in terms of functions (for presenting different interface formats and for allowing different control behaviour) and in terms of transitions (those engaged by the operator, the automatic mode transitions, and both manual/automatic transition). Figure 4 - Observed frequencies of Mode Types The flexibility dimension regards the capacity of automation to change the responsibility and the allocation of a certain task or activity. The flexibility can be characterized in - The change of the levels of automation for a given task depending on some context parameters or some operator selections - Delegation: the change of the task allocation of a subset of tasks: for example a task belonging to the action implementation class can be dynamically assigned to the operator or to the system on the basis of the context information or, again, some operator selections. Flexible automation may have effects on several dimensions of the human performance such as mental workload, situation awareness and user acceptance [13]. Lastly, the reliability dimension regards the degree of correctness in the results or behaviour of the automated system. Studies [7] and [19] report effects on performance and workload due to low automation reliability and they give general guidelines for mitigating those effects in case full reliability cannot be guaranteed. INTERACTING WITH AUTOMATION As shown in the previous section, automation is characterized by several dimensions. Those dimensions can be used to conduct an analysis of a given automated system and depending on the required accuracy one can select less dimensions or try to define new ones or, again, considerate intermediate values in each dimension. Varying the state of a given dimension, we can possibly measure different effects on the quality of interaction. The following part of this literature review aims to address the impacts of automation on the front-end operator. For each impact a set of pertinent studies is reported along with results and possible guidelines on the mitigation of the impacts. SITUATION AWARENESS Situation awareness is a topic widely discussed in the scientific literature. Research studies aim to address how to effectively measure situation awareness, how to define it and what it is impacted by. This section will focus on the latest point. Several works show evidences of automation affecting situation awareness: Parasuraman in [17] points out that automating the decision-making functions may reduce the operator awareness due to the fact that humans are incline to pay less attention to changes made by other agents. [4] compared pilots SA across three automation concepts that varied in the responsibility of the traffic separation. In the first concept, pilots could use a conflict resolution tool that enabled self-separation and bad weather avoidance. The concept 2 consisted in the air traffic controller taking care of the traffic separation task but pilots still had the same tools on the flight deck. In the last concept a ground based automation was introduced and used for conflict detection and resolution; flight deck was equipped with a tool that allowed pilots to deviate in case of bad weather. The Results showed pilots had higher SA in the first concept. This is a confirmation of both Parasuraman study and [5] who performed a similar experiment on pilots and obtained a higher SA in the manual and interactive concepts of automation. SA, however, is also affected by other dimensions. High workload for example is considered to lead to low SA due to cognitive tunnelling. In general, comparisons between studies about SA are delicate tasks: SA may be easily influenced by the methodology and during the experiment. SA is also affected by the user interface designed for a given experiment, thus, a promising automation concept may produce low SA values due to a poor user interface design. FEEDBACK – WARNING – ATTENTION – BOREDOM Feedback is considered to be one of the main problems with automation [15]. Back in 1990 Norman claims that the problem about automation is not the automation itself but rather the way it is designed, the poor and inadequate usage of feedbacks, which is connected to the insufficient level of intelligence of the automation: Norman stated that automation should be made either less intelligent or sensibly more intelligent in order to correctly support the operator in complex domains. But is the automation more intelligent after more than 30 years? Probably it is, but the complexity of the task to be supported is also more complicated. It is conceivable that these two elements (the automation intelligence and the tasks complexity) will have parallel trends through the time. Norman also claims that the reason why automated systems provided poor feedback was because feedback was under considerate by designers. Underconsideration, in turn, was due to the fact that automation doesn’t really need feedbacks or dialogues to work unless something goes wrong. Feedback is certainly an important concept to be studied in human automation interaction, however there’s a need to expand this concept: feedback a piece of information a user expect after executing a certain action. With automated and autonomous systems it is necessary to prompt some information to the operator even it is not related to a previous command and this information may be the basis for a possible action by the operator: an augmented notification, a feedforward. Attention and boredom have been studied by several researchers: Cummings in [2] set up a low task load experiment organized in three different levels that required operator input every 10, 20 and 30 minutes. The operators had to control unmanned aerial vehicles in a simulation environment. As expected, the top performer was the one who spent most of the time in an attention or divided attention state. Figure 5 - Attention Management as a function of time (M. Cummings) Surprisingly, the other top 4 performers spent at least on third of their time in a distraction state suggesting that low task load environments that induce boring can be effectively managed with attention switching and supporting this practice can be a promising design strategy. Authors also highlighted how there was no observable relationship between amount of distraction and performances. In one study of 2001 [14], Nikolic and Sarted explored the solution of splitting tasks and information about automation across different sensory modalities. They run and experiment in which feedback about automation was presented on the peripheral vision of the operators and compared this situation with the normal one in which all the information is presented in a direct way. They found evidence that peripheral visual displays leads to a better detection performance for unexpected events and faster response time. Moreover, this kind of feedback didn’t affect the performance of concurrent visual tasks more than traditional feedback mechanisms. A similar but more comprehensive approach was used by Hameed, Ferris, Jayaraman and Sarter in [10] where both peripheral visual and tactile cues were used to support task and interruption management. In this experiment the cues were used to indicate the need to pay attention to a separate visual task. The cue was characterized by three main parameters: the domain, the importance and the expected completion time respectively represented by location, frequency and duration of the cue. Detection rate was higher with both tactile and peripheral cues compared to the baseline condition but the results also put in evidence that erroneous task switching are usually due to misinterpretation of the cues. Thus deeper research on how to implement appropriate cues for specific domains is required. The automotive domain shows advanced results in this field: J. Scott and R. Gray in [22] examined the effectiveness of rear-end collision warnings presented as tactile, visual and auditory cues. They registered reaction times (elapsed time between the warning presentation and the breaking action of the driver) to the different warning modalities and showed significant advantages for tactile cues compared to visual or auditory. A basic difference between the previous studies is the absence of the interpretation component of the cue: drivers didn’t have to understand why was the warning presented, they had to hit the break in any case. Some guidelines on the design of multimodal information presentation are given in [20] by Sarter. Guidelines are divided in specific topics such as the selection of modalities, mapping between modalities and tasks or type of information, the usage of multiple modalities at the same time and the adaptation of multimodal information presentation. WORKLOAD Workload reduction is one of the reason for the introduction of automation. Unfortunately this benefit has not been as straightforward as expected right before the introduction of automation. As Sarter and Woods observed [9], workload (and errors) was not reduced but only unevenly distributed over time –generating the so called clumsy automation- and sometimes also between the operators working as a team. The authors also point out how the workload changed in the quality dimension due to the fact that the typical tasks are no longer of active control type but they shift to supervisory control, generating attentional needs in part covered in the previous section. In [8] Endsley analysed the level of automation effects on performance, situation awareness and workload. Results showed operator workload reduced when the decision making portion of the system was automated. This reduction however did not lead to significant performance improvements. Figure 6 - Workload distribution in Endsley study Endsley proposed a 10-level LOA taxonomy and monitored the workload in each level. The results are summarized in Figure 6 INTERACTION TECHNIQUES There is no formal definition of interaction technique but the common understanding of this concept usually involves the following components: a combination of input/output devices (e.g. keyboard, mouse and monitor; or touchscreen tabletop etc.) one or more software modules that translate the user inputs into computer commands and provides feedbacks and notifications for the user(s) The way the input/output devices are used and the type of language resulting from the enabled dialogue are what we can usually refer as interaction techniques. During the last years several new interaction techniques have been used by researchers in different fields. The ATM has its own examples too although for many reasons (e.g. preserving safety, cost of the certifications, heterogeneity of the technology providers etc.) it is not the leader field in introducing this kind of innovation. Many researchers spent a vast effort in tabletop systems studies. Persiani, De Crescenzio, Fantini and Bagassi in [18] realized TABO, a tabletop-based interface to support complex simulated environments analysis. TABO was used for the visualization of Air Traffic Control scenarios adopting the “God’s eye view” mode and enabling a multi-user collaboration. Users were allow to interact with the interface trough a wireless mouse. Figure 7 - The TABO interface Objective of the experiment was to enhance the perception of depth and give more awareness about the vertical separation of airplanes. In 2011 Conversy and his colleagues realized a comprehensive system to support Air Traffic Control collaboration with a TabletTop [1]. Conversy highlights how new trends in ATC systems tend to reduce the collaboration dimension in the work environment although the collaboration itself is a key to safety and efficiency. After several interviews and workshops with real users, they identified a set of requirements to support collaboration and applied them in the development of the multi-user tabletop surface. Recently a more sophisticated interaction style has been used by Hurter [11] to find a solution that could replace the paper strips used by air traffic controllers. Hurter developed a novel system for ATC that allows interaction through augmented paper and digital pen. In this way controllers can still use tangible artefacts but still take advantage of the support provided by the digital system. Figure 8 - The Strip'TIC system in [11] Strip’TIC was designed to support en-route controllers in the separation assurance task. The authors received good feedbacks about the virtual/physical strip duality and about the interaction with the digital pen, especially for the selection task. The Strip’TIC system is a good example of transition between the traditional interaction styles represented by the WIMP interfaces and the more natural interfaces that are gaining importance in the last years. This transition is not trivial as it’s not trivial the design of new interfaces using new technology. In general, the risk is the one outlined by Wigdor and Wixon in [23] that is designing new interaction by just transposing the old ones. For example the GUI interaction designed to work with the mouse is (or at least should be) radically different by the one enabled with natural gestures. There is a considerable amount of research trying to define methods and guidelines for the design of the so-called Post WIMP user interfaces. This kind of research has started in the 90’s right after the commercial affirmation of the WIMP interfaces. It highlights the principal drawbacks of the WIMP GUIs like in [3] where we can find: the complexity of the interface grows faster than the complexity of the application expert users often leave the point and click actions (which are the basis of the WIMP GUIs) for the keyboard commands WIMP were designed for office kind of tasks 3D data is not easily explorable They are designed for a single desktop user who controls objects that have no autonomy. The interaction is one channel at a time. “WIMP GUIs based on the keyboard and the mouse are the perfect interface only for creatures with a single eye, one or more single-jointed fingers, and no other sensory organs” Despite all these disadvantages, the controller positions are currently developed on the top of the WIMP paradigm. The new interaction paradigms will not probably replace the WIMP GUIs in every domain as the GUIs did not with the command line interfaces [23]. Each new paradigm will more likely find its own niche in which is the most suitable and used. A research activity in those fields (and ATM does not make exception) is needed to identify the most promising interaction techniques. The research I will carry on will focus on the introduction of a gesture based interface. There are several motivations for this choice: The TRL of the devices that enable the gesture based interaction style is by now high enough to permit a reliable utilization. Gesture interactions have gain importance with the success of the touch devices but there is a growing interest in a new generation of devices that allow free hand gesture interaction (see ENABLER TECHNOLOGIES for details). Gestures can be designed to be as natural as possible and they can provide an high engagement in the interaction process. The devices can be easily found in the market and the price is usually much lower (around 100€) than the one for tabletops or for complex virtual reality systems. Moreover, they can also be used as a monitoring tool to detect different conditions of the user (boredom, distraction, engagement, fun etc.). ENABLER TECHNOLOGIES At the moment three similar technologies have been identified for the development of this research. Figure 9 - The Leap Motion controller The Leap Motion Controller. The Leap (www.leapmotion.com) is a little controller device able to track hands and fingers of the user with a very high precision in the 3D space (1/100th of a millimetre). All the sensing technology and gesture recognition software run inside the device, which is equipped with a dedicated CPU and a set of LEDS and sensors for the motion capture. The Leap is now under testing by a selected but big group of developers and will be delivered in may 2013 together with a rich set of APIs. 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