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ScenarioMethodology
David AlexanderUniversity College London
Wisdom: ability to take decisionson the basis of principles,experience and knowledge
Knowledge: understanding of howthings function (or should function)
Information: description ofphysical and social situations
Data: basic facts and statistics
COMMUNICATION
Source: Yi-Fu Tuan..?
DETERMINISMCause Effect
PROBABILITY(constrained uncertainty)
Cause Single, multiple or cascading effects
THE KNOWN
THE UNKNOWN
PURE UNCERTAINTYCausal relationship
unknown
Greyarea
known knowns- things we
know
Modified Rumsfeld Classification
unknown knowns -things we
don't realisewe know
known unknowns -things we
know we don't know
unknown unknowns -things we
don't know we don't know
Cascading effects
Collateral vulnerability
Secondarydisasters
Interaction between risks
Climatechange
Probability
Indeterminacy
"Fat-tailed" (skewed)distributionsof impacts
Controllability
Controllable Uncontrollable
Uncertainty
HighAdaptive
managementScenarioplanning
Low Optimal control Hedging
Scenario planning in relation touncertainty and controllability
RESILIENCE
Social
Tech
nica
l
Physical
Psych
ological
naturalsocial
technologicalintentionalcompoundcascading
CLIMATE CHANGEADAPTATION
DISASTER RISKREDUCTION
SUSTAINABILITYSCIENCE
OTHER HAZARDSAND RISKS
scenario: Latin scena or scene: "postulatedsequence or development of events"
"focussed descriptions of fundamentally different futures presented in coherent
script-like or narrative fashion"(Schoemaker 1993)
"hypothetical sequences of eventsconstructed for the purpose of focussing
attention on causal processes anddecision-points" (Kahn and Wiener 1967).
Definitions
Scenario: "a systemic method for thinkingcreatively about possible complex anduncertain futures. The central idea...is to consider a variety of possiblefutures that include many of the
important uncertainties in the systemrather than to focus on the accurate
prediction of a single outcome."
(Peterson et al. 1993)
Herman Kahn 1960s, Rand Corporation,Santa Monica, CAthe problem of projecting economicchanges into an uncertain future
Royal Dutch Shell 1980s(Pierre Wack)possible fluctuations in the future price of oil.
History of the scenario"socio-economic futurology"
Mitigation
Scenario methods fordisaster risk reduction
Hypotheticalscenarios
Hazard
Response Vulnerability
RiskImpact
evolution
developmentof thescenarioevolution
timezero
formal evaluation of theoutcome of the scenario
consequencesat time n
Scenariomethodologyin planning
consequencesat time 2
consequencesat time 1
referenceevent
initialconditions
evaluation ofthe progress
of the scenario
historicalanalysis
hypotheticalingredients
C
C
CC
EE
E
E E E
Event
EventC – causeE - effect
C
E
E
E
E
C
E/C
E
E
E
E
E
E
E
E
E/C
(a) (b)
MAGNITUDE& FREQUENCY
KNOWLEDGESCIENCE
LEGISLATION
IMPLEMENTATION
COMPLIANCE
LAG
LAG
LAG
CUMULATIVELAG
EVENTS
Learningprocesses
Improvedsafety
Lessonlearned
Change andinnovation
Experienceand theory
Recognition andcomprehension
Lesson tobe learned
• Unexpected event
• New circumstance
• Error• New
practice
Personalor privateinterestsPublic
interestCultural
acceptability
LESSONS...LEARNED?
Sustainablelessons Uncertainty,
unpredictability
LESSONS...LEARNED?
Incentivesto learn
• a model simplifies reality inorder to make it understandable
• scenarios help bridge the gap betweentheoretical studies and the need tosolve pressing practical problems.
Scenarios are a form ofcommunications model
• scenario modelling is a technique forelucidating situations in the face ofuncontrollable, irreducible uncertainty
• scenarios must strike a balancebetween continuity and surprise
• scenarios involve a range of possibleoutcomes - the envelope of uncertainty.
Conclusions
• chunking: aggregation of smallquanta of knowledge into meaningfulassemblages
'hedging': to limit or qualify byintroducing conditions or exceptions
• scenarios are moreflexible than forecasts.
Conclusions