GOTTLIEB DAIMLERUND

KARL BENZ-STIFTUNG

A collegium of theGottlieb Daimler andCarl Benz Foundation

Austin, Berlin, Zurich, Munich

HIGH RISK ENVIRONMENTSGROUP INTERACTION IN

Prof. Dr. Gisbert Frhr. zu PutlitzDr. Diethard Schade

Board of Management of the Gottlieb Daimler and Karl Benz Foundation

Introduction

This brochure presents an insight into the work of the Ladenburg Collegium ”Group Interactionin High Risk Environments”. More importantly, it demonstrates how the results of the collegium’sresearch projects find application in real-life situations.

In this collegium, scientists are investigating communication behaviour of people working inhigh risk environments – for example in the cockpit of an aircraft, in the operating room ofa hospital or in the control room of a nuclear power station, where mistakes or failure mayhave serious and far-reaching consequences. Chaired by Professor Rainer Dietrich, a psycholinguistfrom the Humboldt-University of Berlin, psychologists, linguists, and neuropsychologists cometogether with practical experts from the airline industry, medicine, and nuclear reactortechnology to find new strategies to understand and even prevent so-called ”human error”in these fields.

This project clearly demonstrates what the work of the Gottlieb Daimler and Karl BenzFoundation is all about: namely, contributing to the solution of current questions and problemsthrough the formation of interdisciplinary networks of experts. The Foundation is exploringnew methods of interdisciplinary research, which are accompanied by a continual dialoguebetween theory and practice. The interdisciplinary Ladenburg Collegia combine the searchfor solutions to socially relevant questions with new, networked research methods in orderto explore the ”reciprocal relationships between humanity, environment, and technology”.In these collegia, scientists from various disciplines work together with practical experts overa period of three to five years. Jointly they establish a research program, define the individualprojects within the program, and review the results of their research at meetings held biannuallyat the Foundation’s headquarters in Ladenburg.

We would like to thank Professor Dietrich, chair of the collegium, who initiated this researchprogram, the members of the collegium, and their assistants in the research projects. Specialthanks must also be extended to the companies Swissair and Lufthansa CityLine, the Gesellschaftfür Anlagen- und Reaktorsicherheit (GRS), and the CityLine Simulator & Training GmbH(CSTBerlin) for their support.

Content

Structure of the collegium 4

Projects:

Group interaction under threat and high workload 8

The effects of different forms of co-ordinationin coping with workload 10

Group interaction in high risk environments:Aviation 12

Group interaction in high risk environments:Liguistic factors 14

Language processing 16

Task load and the microstructure of cognition 18

Communication in nuclear power plants 20

Impressum 22

Structure of the collegium

The InterCity Express train wreck at Eschede, Germany, the MD 11 crash near Halifax, Canada,the nuclear plant accident at Chernobyl. In every case in which a catastrophe occurs duringthe operation of a high-tech system, the question remains the same: man, machine ornature? Where does the ”cause” lie, which takes the blame? More often than not, a clear”cause” is not to be found quickly – sometimes ever at all – despite the overt efforts of allexperts involved. And even when and if an answer has been found, only rarely is the questionregarding the amount of human error involved easy to answer. If a landing airplane is forcedto leave the runway due to strong side winds, is this to be termed ”due to natural causes”?Or should the air traffic control have informed the pilots in greater detail regarding thestrength of the winds they were to encounter, and if necessary ask other neighboringcontrollers or even close the airport for a short period of time? Does it come back down to”human error”? But shouldn’t the automatic security system in the airplane have warned thepilots of the possibility of a one-sided touchdown before it was too late to stop theprocedure, forcing them to land? Is inadequate technical machinery to blame?

Group Interaction in High Risk Environments (GIHRE) is a research project sponsored by theGottlieb Daimler and Karl Benz Foundation. For the first time, specialists from the fields ofaviation, medicine, and nuclear power have started a joint venture with social- and work-psychologists, biological-psychologists, psycholinguists, and linguists. Together they areinvestigating the regularities behind and questions regarding the origin of behaviour that canlead to catastrophic consequences, the exact localisation of the various fatal behavioralpatterns, and the effects of typical and atypical working conditions, such as time pressure,stress and pressure under danger, and cultural-specific communication routines.

There are many different types of professions that present a risk either to those individualsworking in them and/or to others that they service: fire fighters, members of rescue teams inthe Alps or in earthquake, tornado, etc. zones, operating teams in the operating room (OR),decision makers in large chemical plants, engineers in nuclear power plants, airplane andspace mission flight crews, and many more. For the research done in the Collegium, threeworkplaces were selected: the nuclear power plant control room, the operating room, and theairplane. During the course of the investigations, the intensive care unit has been added to

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GROUP INTERACTION INHIGH RISK ENVIRONMENTS

GIHRE

Structure of the collegium

this list. These are typical examples of the environments listed above, and yet also differtypically from one another, covering the range of variables through which such professionsdiffer from one another regarding the size of the team, the time element, and the effectsinvolved that malfunctions and error can have on the environment and the people affectedby it. In all of the working environments, the team members are typically responsible for manydifferent both mental and motor tasks simultaneously, which they must be able toaccomplish, if necessary, in unexpected, dangerous situations under enormous time pressureand stress. Other typical differences, in addition to the variables listed above, lie in the actualdanger and risk for the team members and in the amount and type of damage for humansand the environment involved in the event of a catastrophe.

The last forty years have seen tremendous efforts in the improvement of security in man-machine systems. Better education, more real-life orientated training of the personnel, and thedevelopment of more sophisticated control systems have increased safety in all fields in whichhigh technology has become a part of everyday operations. One of the most visible measuresin the training arena has been the development of training methods that apply to the teamas a functional unit. One example of this is the successful implementation of Crew ResourceManagement (CRM) in the training of cockpit crews, which has in return lead to an increasedneed for methods with which to rate the CRM training’s final outcome. Another example canbe seen in the attempts to integrate these training methods from aviation in areas with similarteam structures, such as that of the operating room. The research done in the GIHRE-subprojects headed by the Swissair CRM-trainer Capt. Werner Naef and by psychologist Prof.Dr. Gudela Grote of the Swiss Federal Institute of Technology in Zurich focus on these factors.

Linguistic analyses of verbal interaction in these areas have proved that the misunderstandingof phonetically, structurally or semantically ambiguous utterances can lead to trouble, danger,and disasters. The subprojects at the Humboldt-University of Berlin, head by the linguist Prof.Dr. Manfred Krifka and the psycholinguist Prof. Dr. Rainer Dietrich, concentrate on an analysisof linguistic factors and attempt to decipher their cognitive roots. These findings can then besupported by bio-psychological research being done by Prof. Dr. Werner Sommer, also of theHumboldt-University of Berlin.

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Structure of the collegium

Other possible sources of danger within ”high risk” environments could be communicationconflicts caused by the overgeneralisation of status roles, the structure of information flow orthe problem solving culture in the specific working environment. Attitudes also seem to affectbehavior in various ways in different phases of a hazardous situation. Social-psychologicalstudies tell us that the immediate problem in a disaster situation is neither uncontrolledbehaviour nor intense emotional reaction, but deficiencies in co-ordination and organisation,which are then complicated by people acting upon individual (and, often conflicting)interpretations of the situation. Situation awareness is a key concept in decision making inhigh risk settings, yet our understanding of decision making within aircrews and other teamsin highly stressful situations is rather limited. Prof. Dr. Robert Helmreich, head of The Universityof Texas at Austin’s Human Factors Research Project, offers a structural analysis of suchcommunication and interaction processes in the hospital environment. In an experimentalstudy, Dr. Oliver Sträter of the German ”Gesellschaft für Anlagen- und Reaktorsicherheit” alsolooks at the effects of the structure of the nuclear power plant environment oncommunication within the control room team.

GIHRE’s ultimate goal – to assist in the better understanding of team interaction andcommunication under conditions of high task load, stress, and danger – directs the researchof all seven subprojects presented in this brochure. Through the co-operation with Europeanand international authorities in the field of aviation, with individual hospitals or hospitalgroups in the field of medicine, and with independent testing facilities in the field of nuclear

power, it can now hope to play a substantialrole in the defining and re-defining of tools forthe training, rating, and describing ofinteraction and communication in theseenvironments.

Collegium Head: Prof. Dr. Rainer Dietrich (left),Humboldt-University of BerlinCo-ordinator: Kateri Jochum (right)

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Structure of the collegium

7

Abbreviations: NPP = Nuclear Power Plant; OR = Operating Room.

SMALLAirplane

MIDDLEOR

LARGENPP

Moderatelystandardisedand very fast

Airplane

Informal and fastOR

LOCALAirplane

PERSONALOR

ENVIRONMENTALNPP

Proceduralisedand comparably slowevent development

NPP

Project Head:Robert L. Helmreich,

Department of Psychology, The University of Texas at Austin, USA

Research assistants:J. Bryan Sexton

Group Interactionunder Thread and High Workload

The project centers on group performance during threat and high workload, in line withresearch conducted in the field of social psychology by the University of Texas Human FactorsResearch Project over the past 20 years. The initial focus of the research was on groupprocesses and communication in the aviation cockpit. Under support from the Foundation,relationships between perceptions of the culture of safety and the successful management oferror and error outcomes were demonstrated by investigator Bryan Sexton.

The research has expanded to encompass medicine, another high risk environment repletewith safety-critical interpersonal interactions. Medical error is strikingly common, its effects areexpensive, and population based estimates of deaths due to preventable medical error in theUnited States range from 44,000 to 98,000 annually. Also, there is a dearth of research in thisfield on group processes and their relationship to patient outcomes. The medical environmentoffers a unique opportunity to examine individual, team, organizational, and systemic factorsthat relate to critical outcomes, such as patient morbidity and mortality.

To provide a conceptual framework for the examination of teamwork in medicine, a modelcreated by the University of Texas Human Factors Research Project known as the Threat andError Management Model (TEMM) has been adapted for the medical environment. The modelspecifies latent (systemic, cultural, etc.) threats as well as expected and unexpected events anderrors that may beset groups working in environments such as the operating theatre orintensive care unit. The Model identifies five types of errors – violations of procedures,unintentional procedural mistakes, communications breakdowns, errors due to lack ofproficiency, and decisions causing unnecessary risk. It further depicts threat and erroravoidance and detection behaviors. These are the actions taken by groups to deal with threatand error and represent areas where training can lead to greater safety. If threat and erroravoidance and management are unsuccessful, the task becomes management of theundesired patient state that results. Faced with an error, groups can fail to respond, theiractions may mitigate the situation, or they may exacerbate it to an undesired patient state oreven an adverse or sentinel event.Guided by this model, an assessment of the perceptions of medical personnel relevant tointerpersonal functioning has been initiated, using a survey instrument designed to assess the

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safety culture in medicine and participant attitudes regarding teamwork and error. Thisfollows the model of research previously employed in aviation. The project’s central area ofinvestigation is the intensive care unit (ICU), where investigations are being carried out inmore than 100 ICUs in the United Kingdom. The research design will allow the project todefine the culture of safety in each ICU and to relate the culture and attitudes andperceptions of teamwork and error to patient outcome variables. The underlying hypothesisis that by understanding the culture and the perceptions of teamwork in the face of threatand error, it will be possible to predict some of the substantial variability in patient outcomes.Furthermore, an understanding of the factors associated with threat and error should help inthe definition of organizational and training interventions to optimize the performance ofindividuals, teams, and organizations.

Robert Helmreich is professor of psychology at The University ofTexas at Austin, where he has taught since 1966, and is principal investigatorof the University of Texas Human Factors Research Project. This group studiesindividual and team performance, human error, and the influence oforganisational and national culture on behaviour in aviation and medicine.Helmreich received his bachelor’s, master’s and doctoral degrees from YaleUniversity. He is former editor of the Journal of Personality and SocialPsychology and a former member of the Committee on Human Factors ofScience, the Committee on Space Biology and Medicine Administration atthe National Academies of Science. He also is a former member of theResearch and Development Advisory Committee of the U.S. Federal AviationAdministration. He is a member of the U.S. National Patient Safety FoundationResearch Board.

www.psy.utexas.edu/psy/hemlreich/nasaut.htm

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University of Texas Medical Threat and Error Management Model

Diagnostic and ErrorAvoidance Behaviours

Adverse Event

SystemLatent Threats Organizational Professional

Unexpected Eventsand Risks

External ErrorATC, etc.

Violations - CommunicationProcedural - Proficiency

Operational Decision

External Threats

Error Management Behaviours

Expected Eventsand Risks

Inconsequential UndesiredPatient State

AdditionalError

Undesired State Management Behaviours

AdditionalError

Error MitigratedThreat Managed

CRM Behaviours

Outcomes

Final Outcomes

CRM Behaviours

Project Head:Gudela Grote

Institute of Work Psychology, Swiss Federal Institute of Technology (ETH),Zurich, Switzerland

The effects of different forms of co-ordinationin coping with workload

In institutions operating in high risk environ-ments there have been strong efforts madewithin the last decade to increase the level ofstandardisation in order to make the system’sbehaviour more predictable and controllable.At the same time, high levels ofstandardisation pose major disadvantages aswell, mainly due to the reduction of asystem's capability to adequately act oninternal and external disturbances of normaloperation. A promising, though still poorlyoperationalised concept for combining highlyreliable and explicit co-ordination with theneeds of flexibility is ”heedful interrelating”,i.e. the deliberate efforts by all actors toconstantly (re-)consider the effects of theirown actions in relation to the goals andactions of others.

Using data collected within GIHRE’s aviationand medicine sub-projects in simulatortraining sessions and during actual surgeries, different forms of more or less standardised andalso more or less explicit co-ordination in cockpits and operating theatres and their effects onteam performance under varying degrees of workload will be described and compared.Aviation represents one of the foremost examples of a very high degree of standardised co-ordination; standard operation procedures are established for both normal and abnormalsituations to an extent that even disturbance handling has been partially automated.Medicine, on the other hand, may be considered to be one of the least proceduralised ofhigh risk environments, with only fairly recent attempts at increased standardisation, e.g. aspart of quality assurance measures. Thus, a comparison of the aviation and the medical fieldprovides a unique opportunity to study the advantages and disadvantages of high vs. low

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Communication in the operating roomsis non - standardised

degrees of standardised co-ordination at a time when research results can potentially have amajor effect on changes in the fields under investigation.

An example of the standardised phraseology for departure in the airplane cockpit:

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Gudela Grote, born 1960 in Wiesbaden, Germany, professorof work and organisational psychology at the Swiss Federal Instituteof Technology (ETH) in Zurich, studied psychology in Marburg andBerlin, Germany, and received her Ph.D. at the Georgia Institute ofTechnology in Atlanta, USA, in 1987. Her main research interests aresafety management and safety culture, the effects of automation,computer-supported co-operation, planning in organisations,multimedia learning, and the relationship between work and personalidentity.

Web site: http://www.ifap.bepr.ethz.ch/

A: REQUEST DEPARTURE INSTRUCTIONS *(details)*

G: LEAVE CONTROL ZONE *SPECIAL VFR* VIA (route)*AT ALTITUDE (figures) FEET / OR ABOVE / BELOW* *(intructions)*

G: UNABLE TO ISSUE DEPARTURE VIA (designator) *(reason)*

G: REPORT *WHEN* READY *FOR DEPARTURE*

G: ARE YOU READY *FOR DEPARTURE*

A: READY *FOR DEPARTURE*

G: ARE YOU READY FOR IMMEDIATE *DEPARTURE*

A: READY FOR IMMEDIATE *DEPARTURE*

G: WAIT *(reason)*

G: WHEN AIRBORNE (instructions)

A = Aircraft radio stationG = Ground radio station

Group Interaction in High Risk Environments:Aviation

It is a well known fact that about 70 percentof accidents and incidents in aviation arecaused not mainly by deficiencies in technicalabilities, but by the lack of successful teamfunctioning in demanding situations. In orderto enhance flight safety, the airline industry isconvinced that human factors skills need tobe promoted and cultivated just as much astechnical skills. In addition to the enlistmentof mandatory multi-modular human factorstraining, the European Commission haslaunched a special research effort in order to develop a behavioural marker set to be used byairlines within Europe to measure and qualify team behaviour. This tool was published in 1998as the "NOTECHS” (non-technical skills), which are defined as "skills that refer to pilots’attitudes and behaviours in the cockpit, not directly related to aircraft control, systemmanagement, and Standard Operating Procedures (SOPs), which influence flight safety.”NOTECHS has four main categories (‘Co-operation’, ‘Leadership and Managerial Skills’,‘Situation Awareness’, and ‘Decision Making’) which are each linked with 3–4 behaviouralelements. NOTECHS’ applicability, reliability and the influence of cultural differences havebeen evaluated, but pilots and pilot unions must also be convinced of the feasibility of validCRM assessment in order to introduce the qualification of CRM skills.

This project aims (1) to validate existing CRM behavioural markers under conditions of highworkload, (2) to compare two behavioural marker sets used for observation, namelyNOTECHS and LOSA (Line Oriented Safety Audit), which differ in the categories and elementsobserved as well as in their rating procedures, and (3) to determine the effects of differentkinds of CRM training through the comparison of the CRM judgements for crews fromdifferent airlines. In the simulator quasi-experiment, video tapes of simulator training sessionsfrom an Airbus 320 and the Canadair Jet fleets have been made. The simulator scenariosconsist of three high workload and one normal workload situation and are standardised foreach aircraft type. Complementary to this information, questionnaires regarding subjective

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Project Head:Capt. Werner Naef

Swissair

Researchers/Scientists:Gerhard Fahnenbruck, Ruth Häusler, Barbara Klampfer

workload for each of the four scenarios as well as questions about team and individualperformance are filled out by each crew member. In a separate questionnaire, the instructorgives an expert rating of the crew’s CRM and technical performance.

The behavioural markers observed for every flight phase in the video analysis stem from thefirst of the three complementary parts of LOSA, the Human Factors Checklist, whereby thethree categories ‘Planning’, ‘Execution’, and ‘Review/ Modify Plans’ are differentiated. LOSA’ssecond and third sections, the External Threat Management Worksheet and the FlightcrewError Management Worksheet, deal with the description of external threats (e.g. weather,ATC, etc.), the description of errors made by the pilots or other people involved, and themanagement of these errors, respectively.

Over and beyond that of the reliability andthe validity of behavioural markers, thequestion arises as to which markers from thetwo mentioned CRM assessment tools(NOTECHS and LOSA) are best able todifferentiate between crews with good andpoor performance under high workload. Aregood team players (high CRM judgement)always good team players, independent oftask difficulty (normal vs. high workloadsituation)? The within-crew comparisons willshow whether team skills are independent of the situation that has to be mastered. In thecurrent project phase, the core interests lie in the relationships between CRM behaviour,errors, team performance in general, and workload. Here the re-occurring questions focus onwhether good CRM performers have better technical and overall performance ratings,whether they commit less or different errors, and/or whether they merely deal differently witherrors, resulting in an error outcome with different consequences.

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Werner Naef, born 1947, studied engineering at the Swiss FederalInstitut of Technology in Zürich. In 1969 he graduated as an airforce pilot andconsequently joined the commercial airlines Swissair. He has been a captainwith Swissair since 1981 and has held several positions, including those asTraining Captain, Instructor- and Checkpilot, Deputy Fleet Chief Pilot, andmember of the pilot selection team. Between 1976 and 1981 he receivedpostgraduate training in psychotherapy and has since been responsible forthe Human Aspects Development/Crew Resource Management Training atSwissair. He is a board member of the European Assoc. for Aviation Psychology,the delegate of the AEA (Assoc. of Europ. Airlines) in the European JointAviation Authorities’ Human Factors Steering Group, and the Swiss CivilAviation Authority’s Human Factors expertWebsite: http://www.swissair.com/about/training/humanfactors.htm

Group Interaction in High Risk Environments:Linguistic factors

Misunderstandings can lead to dangerous situations. Some of the worst accidents in aviation,for example, were caused, in part, by linguistic problems resulting in miscommunication. Inthis project, linguistic malfunctions in the setting of the airplane cockpit are investigated. It isknown that social factors like rank differences between captain, first officer, and engineermay impede optimal performance; the current project looks, more specifically, at linguisticfactors that may have similar effects.

We investigate the linguistic behaviour of flight crews in standardised flight simulator sessions,in which all crews are faced with comparable problems. The project concentrates on anumber of categories and relate those to two non-linguistic variables: The task load demandof the crew at a particular time and the crew’s performance rating.

The analysis of the crew communication is informed by speech act theory and conversationanalysis. Some of the speech act types being investigated are: status reports, reports ofactions of the speaker, prognoses and diagnoses, commands, permissions, verbalisations ofcomplies, reports of intentions, and expressions of emotions. Particular attention is paid toacknowledgements, affirmations, and rephrases that indicate the success of attempts tocommunicate to the speaker. Other categories include explicit references to the speaker, theaddressee or the group, hesitations and hedges (like sort of), evidence for misunderstandingsor corrections, encouragement, politeness, and swearwords. The frequency in which the crewmembers interact with each other and with the air traffic control is also registered.Preliminary evidence has indicated that there are indeed linguistic features that correlate withworkload and crew performance. For example, periods of high workload show a greaterincidence of commands and of explicit references to the group. Interestingly,acknowledgements and emotional words were less frequent in segments of high workload.Crews with good performance showed more explicit group references and, interestingly,fewer commands and more reports of intention.

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Project Head:Manfred Krifka

Institute for German Language and Linguistics,Humboldt-University of Berlin

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Manfred Krifka is currently Professor of General Linguistics atthe Humboldt-University of Berlin, and director of the Center forGeneral Linguistics, Berlin. He was professor of linguistics at theUniversity of Texas at Austin from 1990 – 2000. His main interestsare the syntax, semantics, and pragmatics of natural languages andlanguage typology. He has worked, in particular, on aspect, measureconstructions, questions, and information structure and is the editorof a major journal, Linguistics and Philosophy.

Web site: http://amor.rz.hu-berlin.de/~h2816i3x/

Reports of Intention / Utterance

0.08

0.07

0.06

0.05

0.04

0.03

0.02

0.01

0

A, C: reports of intention in low workload periodsB, D: reports of intention in high workload periods3, 4: reports of intention for two worst-performing crews5, 8: reports of intention for two best-performing crews

A B C D 3 4 5 8

Language processing

Getting airline passengers from departure to destination is a complex task which is comprisedof several hundreds of sub-tasks. The safety and success of each individual flight event areessentially influenced by the completeness, correctness and the quality of the informationflow, i.e., by the linguistic competence and performance of the flight related personnel, mostof whom the passenger never sees or hears. As long as spontaneous oral communication cannot be replaced by any other than human activity, the safety of air traffic depends highly onthe capacity to communicate precisely and efficiently on both the sides of the speaker and ofthe hearer.

The project investigates temporal and qualitative aspects of verbal communication underconditions of low and high task load. The focus is laid on the faculty of an interlocutor toanswer questions while at the same time performing another attention demanding task. Themethodological approach of the project is experimental. The hypothesis under investigationis that answering different types of questions will bind different proportions of the cognitivecapacity: Answering yes/no-questions, for instance, is expected to "cost less" than answersto when-, what-, where- or why-questions.

To a certain degree, the experimental task is intended to simulate conditions of problemsolving in the cockpit, i.e., communication between pilot and co-pilot who are simultaneouslyfocused on their primary task of flying the airplane. This is realised by a particular type ofexperiment within a general experimental paradigm called the dual-task paradigm. Thestructure of the entire experimental task is shown in Figure 1. In this experiment, the subjecthas to manage more or less demanding psycho-motor tracking tasks while answering a seriesof questions about information stored in his/her short term memory. To solve the trackingtask, the subject has to hit a moving target presented on the screen of a PC with the cursorof the mouse. Task load is manipulated by increasing or decreasing the time span available foreach trial; compare Figure 2. If the data created by the experiment confirms the theoreticalpredictions, the findings of the project could contribute to both improvement of trainingmeasures within this environment and to the reconsideration of technical details of cockpitequipment.

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Project Head:Rainer Dietrich

Institute for German Language and Linguistics, Humboldt-University of Berlin

Research assistants:Katja Kühn

Sascha Neuper

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Rainer Dietrich, born 1944, is currently Professor ofPsycholinguistics at the Humboldt-University of Berlin. His mainresearch interests are in the field of language production andsecond language acquisition. He heads the psycholinguisticexperimental lab of the Faculty of Arts II and has conducted anumber of experiments on language processing.

Web site: www2.hu-berlin.de/psyling/

Figure 2: Computer experiment

Figure 1: The dual task-experiment paradigm

Intro phase Question answering phase

Tracking

t

Task load and the microstructure of cognition

When a complex task, such as flying an airplane or performing surgery, becomes moredifficult, it may tax the capacities of the operator. In addition, it may be extremely hard tounderstand and respond to information provided by others. Thus, it may be difficult for asurgeon performing a difficult excision, for example, to understand and pay heed to warningsby the anesthetist that the patient’s blood pressure is falling. This subproject aims tounderstand the effects of such high task load on the internal microstructure of humaninformation processing by modeling important aspects of operator situations in the laboratoryand by recording electrical brain potentials in experiments, which give direct insight intoinformation processing. Understanding these effects may be useful in the optimization ofoperator situations.

In the experimental setting, task load ismanipulated by varying the requirements forthe speed or accuracy of the responses insingle and multiple tasks in which two thingshave to be done simultaneously. For example,the ability to understand verbal messageswhile performing a difficult sensory-motortask of high priority is studied. Theseexperiments will also be conducted withsecond language messages, correlating tocommunication requirements in theenvironments under investigation by theproject as a whole, e.g., in multi-nationalhospital teams and in flight crews. The dual-task experiments in particular are performedin co-operation with other subprojects.

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Project Head:Werner Sommer

Institute of Psychology, Humboldt-University of Berlin

Research assistant:Dr. Jörg Sangals

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Werner Sommer, born 1952, received his diploma inpsychology from the University of Würzburg in 1976. Heobtained both his doctoral degree (1982) and his Dr. habil.(1991) at the University of Konstanz. In 1995, he was appointedProfessor of Biological Psychology and Psychophysiology at theDepartment of Psychology at the Humboldt-University of Berlin.His research interests, among others, are mental chronometryand face recognition.

Web site:http://www.psychologie.hu-berlin.de/bio/seiten/index.htm

As a concrete example, the effects of varying demands on the speed and precision (forceaccuracy) of key presses in response to a signal, which followed a warning stimulus by 1.5seconds, were studied. Contrary to common belief in a speed-accuracy trade-off when highdemands on speed and precision are combined, the quality of performance was hardlycompromised as compared to single demand conditions, indicating that at least in somecircumstances high accuracy can be maintained, even when in a hurry. Because motoric brainactivation prior to the response was similar for both single demand conditions and combineddemand conditions additively, the experiment seems to show that response force andprecision are controlled by relatively independent neural systems.

Communication in nuclear power plants

Whereas only a few human interventions are necessary to run a highly automated nuclearplant while the automatic systems are up and running, "good communication" is one of themajor aspects of safety in nuclear power plants if automatic systems are not workingappropriately or if they have to be shut down for maintenance reasons (i.e., in so-called low-power and shutdown states). In such situations, human beings take over the control of theprocess – naturally these interventions have to be planned and co-ordinated within a groupin the control room as well as at the location itself.

Up until now, these communication and co-ordination aspects have been of lesser interest insafety assessments, which generally focused on full power states and the so-called designbased accident (i.e., accidents that have been anticipated within the layout of the system andthe management of which are therefore highly trained). All safety assessment methods havebeen optimised to assess the safety significance of humans in such situations. Consequently,the predictive methods for human reliability assessment (HRA) are not designed to describe orpredict the effectiveness of communication in states over and above design-based accidentsor low-power and shutdown states. However, such situations have become an increasingfocus of attention in the last few years, revealing the lack of research of human aspects ofinterest in such states.

During the first project phase, about 231 operational events with human errors in nuclearpower plants (NPP) were analysed for communication problems. It was observed that roughly10% of these showed communication problems as being the major important contributor tothe event. Further investigation of the underlying causes for the communication problemsrevealed a dependence on factors like workload or situational pressure; in addition, atendency for the communication problems to lead to cognitive compensation strategies, suchas the reduction of problem spaces or the set of goals, was shown.

However, operational experience also presents examples of good communication that can beobserved in high workload conditions. The detailed analysis of the events shows that thisseeming contradiction is resolved when the communication task is related to the requiredoperational task within the technical system. Communication problems seem to be

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Project Head:Oliver Sträter

Gesellschaft für Anlagen- und Reaktorsicherheit, Garching, Germany

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Dr. Oliver Sträter has been working for the Gesellschaft fürAnlagen- und Reaktorsicherheit (GRS) since 1992, which isresponsible for research and development regarding the safety ofnuclear power plants in Germany. He is also a faculty member of theInstitute of Ergonomics at the University of Technology Munich,focusing on Human Reliability and Software-Ergonomics. Havingreceived his degree in the fields of engineering and organisationalpsychology, his work mainly focuses on the assessment of thecognitive aspect of human reliability, the interrelation of cognitiveand organisational causes, and the analysis of operationalexperience regarding human performance.Web site: www.lfe.mw.tum.de/~straeter

dependent on whether the communicative task is considered to be a distraction to thecognitive load caused by the operator’s operational task or is in accordance with it.

The second phase of the project seeks to investigate this effect, i.e., the accordance ofoperational and communicative task and its consequences for the required cognitiveprocessing in an experimental setting. The experiments, which will be performed in the NPP-simulator at the GRS comparable to a fully computerised control room, will measure thequality of communication compared to the way in which the contents of the operational taskmatch the communication requirements.

Eye-tracking devices will be used to trace the current status of the operators’ cognitiveprocessing of the operational task; communication quality will be measured based ondifferent types of transients (system failures). The underlying hypothesis can be stated as such:If the communicative task is in accordance with the needs of the operator’s operational task,no communication problems – perhaps even good communicative performance – will beobserved. However, if the communicative taskdoes not match the needs of the operator’soperational task, communication problems will beobserved, and their causes will be similar to theones observed in the event investigation analyses.

Previous investigations have shown that theproblem of communication is expected to be ofmuch greater relevance in a computerized controlroom (as in Figure 2) than it is in a conventionalcontrol room (as in Figure 1). Whereas in thelatter the operators have a more shared workingenvironment, each operator works ratherindividually on his own terminal in thecomputerized working environment.Computerized control rooms are already standardin many technical environments, including thoserepresented in other GIHRE-projects. Fig.2: Computerized control room

Fig.1: Control room of a Nuclear Power Plant

Impressum

Group Interaction in High Risk Environments (GIHRE)Berlin, March 2001

Project Head:Prof. Dr. Rainer Dietrich

Co-ordination:Kateri Jochum

Humboldt Universität zu Berlin(Sitz: Schützenstr. 21)Unter den Linden 6

10099 BerlinTel. +49-30-201 96-673 and 201 96-772

Fax: +49-30-201 96-729URL: http://www2.hu-berlin.de/GIHRE

Editors:Prof. Dr. Rainer Dietrich

Kateri Jochum

Artwork:Karsten Reuß

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