Transcript of "Technical Challenges of Real-World Agent-Based Modelling"
Thomas French29th May 2013www.sandtable.comTechnical Challenges of Real-World Agent-Based ModellingThursday, 30 May 13
Outline• What is ABM?• Why use ABM?• Classic ABM example• Real World ABM• Three Key Technical ChallengesThursday, 30 May 13
“Essentially, all models arewrong, but some are useful”G.E. Box (1987)Thursday, 30 May 13
ABM in a nutshellAGENTENVIRONMENTSENSORSMESSAGESACTIONSPERCEPTSOBJECTACTUATORSBased&on&Bordini&et&al&&(2007)Thursday, 30 May 13
Why are we talking about ABM?• It shows promise forunderstanding complexsystems:– heterogeneous andadaptive actors– complex interactions:interdependencies;feedback loops– dynamic environment• It provides an accessiblemetaphor for modelling– modelling individuals• More and more data isavailable for our models- Finer levels ofgranularity• Computing power isavailable on-demand- Costs continue toreduceThursday, 30 May 13
Classic ABM: Schelling Segregation Model• Developed by Thomas Schelling in 1970s.• Study racial segregation of populations emergingfrom individual discriminatory behaviours.Thursday, 30 May 13
Technical ChallengesBUILD VALIDATE EXPERIMENTDesigning*andbuilding*modelsBuildingConﬁdence*in*ModelsConductingLarge?ScaleExperimentsHARD VERY,*VERY*HARD VERY*HARDThursday, 30 May 13
Building ModelsBUILDVALIDATEEXPERIMENTBehavioural+DataSurveyDataAssumptionsIntuitionAnalyse BuildIndividual+Agent+AttributesBehaviour+TreeEnvironment(e.g.+Media)Representative+PopulationData+SourcesSimulationComponentsThursday, 30 May 13
Validation - Building ConﬁdenceVALIDATEEXPERIMENTDoes the implementedmodel reﬂect thereal-world system?Thursday, 30 May 13
Validation – Establishing CriteriaA framework for evaluating state of validity of modelsfor on-going monitoring.VALIDATEEXPERIMENTVALIDATIONINTERNALVALIDATIONEXTERNALVALIDATIONModel&implemented&correctlyBehaviours&predicted&make&sense&/&are&logicalModel&stands&up&to&comparison&with&external&dataThursday, 30 May 13
“Nothing is built on stone;all is built on sand. But we mustbuild as if sand were stone.”J.L. BorgesThursday, 30 May 13
Thanks for firstname.lastname@example.orgThursday, 30 May 13
Further studyBook:• John Miller and Scott Page: Complex AdaptiveSystems: An Introduction to Computational Modelsof Social Life (2007)Coursera:• Scott Page: Model Thinking• https://www.coursera.org/course/modelthinkingThursday, 30 May 13
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