SCID Final meeting - Staging Abstraction

Staged Models for Interdisciplinary Research

Combining Relevance and Rigour

The SCID Project Members(but particularly in this part of the work:

Luis Fernandez Lafuerza, Louise Dyson, Bruce Edmonds and Alan McKane)

Rigour and Relevance

With complex systems one is faced with using:– A simple model that can be completely analysed– A complicated model including the known processes

• Choosing between rigour or relevance

Often when formal (e.g. physicists) and social scientists collaborate there is some dissatisfaction:

– Formal scientists dislike models they don’t understand– Social scientists dislike models with abstract micro-level

SCID has tested out an approach which uses a (complicated) descriptive model which reflects evidence which is then, itself, modelled with simpler models that can be adequately analysed

Staged Models for Interdisciplinary Research, SCID Final Meeting, Crewe, July 2015, slide 2

Our Basic Approach…

…is to stage abstraction with an intermediate, complex model, that is then, itself, modelled (a ‘KIDS’ approach)• The Data Integration Model (DIM) includes all that is

deemed relevant by social scientists• The simpler models of the DIM are developed by

formal scientists but validated against the DIM

Representation

Simplification

DIM


Reduced Simulation ModelsReduced Simulation Models

Overall Strategy

Data-Integration Simulation Model

Micro-Evidence Macro-Data

Reduced Simulation Models

Analytic Model

Even Simpler Simulation Model

Reported in this

presentation

Currently being

developed


Outline of Model Reduction

Red and green processes were somewhat simplified, also parties and (initially) social network


Comparison of Reduced and DIM Models

Low and high turnout regimes

Broad agreement between models, but different levels and different dynamics in transition region


With Different Kinds of Network

Blue = Clumped Network, Green = With “clumped” network, Red = no network (bistability in transition)


Synthetic Network

Kinds of network

A synthetic network that is composed of small groups with some random inter-group connections resulted in better fit of dynamics


Network in DIM

Fixed vs. Dynamic Networks

Reduced models with fixed ‘clumped’ network (blue) and with a dynamic network where links between households change (red)

Dynamism increases turnout due to diversity of links over time allowing wider influence


Individual vs. Household Immigration

With immigrants of either a lower or higher political interest than natives, individual immigration resulted in higher level of turnout than household immigration, due to asymmetry of influence process

Low Interest Immigrants High Interest Immigrants

IndividualImmigration

FamilyImmigration


Final Comparison

Reduced model + dynamic ‘clumped’ network + household immigration had good fit to DIM turnout dynamics but amenable to complete checking, much simpler and easier to experiment with


What was Learnt?

The comparisons suggested that:• distinctive ‘high’ and ‘low’ turnout regimes exist,

depending on rate of discussions• when in extreme turnout regimes, the system is

stable, whereas in the transition regime turnout can 'flip' between low and high

• the lack of bistability in the transition is due to the ‘locality’ and sparseness of the network

• the dynamism of the network resulted in higher turnout levels

• household immigration reduced turnout compared to individual immigration


Conclusions

• Relevance and rigour combined via a ‘chain’ of highly related models (not in a single model)

• Intermediate abstraction step of a DIM• Enabled social and formal scientists to work

effectively together, each to their own strengths – crucial communication via a (complicated) model

• Each model acts as a check on the other• Policy relevant hypotheses found• Further iterations of model simplification in

progress towards completely analytic models


Thanks!The SCID project:

http://scid-project.org

The Full Voter Model:http://openabm.org/model/

4368

Slides at:http://www.slideshare.net/

BruceEdmonds

Documents

SCID Final meeting - Staging Abstraction