on disciplinary fragmentation and scientific progress stefano balietti, michael mäs, and dirk...
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On Disciplinary Fragmentation and Scientific Progress
Stefano Balietti, Michael Mäs, and Dirk Helbing
ETH Zurich, Chair of Sociology in particular Modeling and Simulations
Social Simulation Conference – Barcelona, 05-09-2014
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Research Questions
Why are some disciplines more fragmented into conflicting schools of thoughts than others ?
Why do disciplinary fragmentation and limited scientific progress seem to correlate ?
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Physics: a Path of Unification
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Physics: a Path of Unification
Isaac Newton(1642 - 1727)
Unified celestial and terrestrial forceswith the law of gravity.
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Physics: a Path of Unification
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Physics: a Path of Unification
James Maxwell(1831 – 1879)
Unified electricity and magnetism in one single force calledelectromagnetism.
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Physics: a Path of Unification
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Physics: a Path of Unification
Albert Einstein(1879 - 1955)
Unified the Newtonian theory ofgravitation and his special relativitywith the theory of general relativity.
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Physics: a Path of Unification
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Physics: a Path of Unification
Steven Weinberg(1933)Unified, on a subatomic level,
the strong force, and the weak force,and the electromagnetic force in once single model calledthe Standard Model.
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
The Social Science Archipelago
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
The Social Science Archipelago
Science is composed of an archipelago of typically smallish and highly cohesive communities (Liljeros 2010).
High between-, low within-group variance. Different social norms apply to different communities.
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Fragmentation in Social Sciences
H. Gintis @ Game Theory and Society Zurich, 2011. “Analytical Foundation of Sociological Game Theory”
With the sole exception of economics, the social sciences are still missing a core theory that everybody acknowledges.
De Langhe R (2009) Mainstream economics: Searching where the light is. Journal of Post Keynesian Economics 32: 137–150.
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Research Questions
Why are some disciplines more fragmented into conflicting schools of thoughts than others ?
Why do disciplinary fragmentation and limited scientific progress seem to correlate ?
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Research Questions
Why are some disciplines more fragmented into conflicting schools of thoughts than others ?
Why do disciplinary fragmentation and limited scientific progress seem to correlate ?
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
References
Vicsek et Al. (1995)
“Novel type of phase transition in a system of Self-Driven particles”. Physical Review Letters 75: 1226–1229
Hegselmann R., Krause U. (2006)
“Truth and cognitive division of labour: First steps towards a computer aided social epistemology.” Journal of Artificial Societies and Social Simulation 9: 1–28.
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Model Description
Scientists explore a 2-dimensional epistemic space of possible answers to a research question
The movement represents the approach The position represents the current view
Simultaneously exposed to 3 forces:
Attraction towards the ground truth Social influence of related opinions Randomness (Noise)
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Formal Model
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Formal Model
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Formal Model
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Formal Model
Position Noise Angular Noise
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Model parameters
Ground Truth– Strength of attraction τ
Social Influence: Radius of interaction R Strength of social influence α
Noise:
Intensity position noise ε Intensity angular noise σ
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Ideal-Typical Model Outcomes
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Ideal-Typical Model Outcomes
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Ideal-Typical Model Outcomes
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Ideal-Typical Model Outcomes
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Ideal-Typical Model Outcomes
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Model Dynamics Explained
Agents move randomly in the epistemic space
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Model Dynamics Explained
Agents enter each other interaction areas
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Model Dynamics Explained
Agents approaches are updated by social influence
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Model Dynamics Explained
New approach is weighted average of own approachand average approach within interaction radius
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Model Dynamics Explained
New approach has a new direction and intensity
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Model Dynamics Explained
Approach is updated immediately
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Model Dynamics Explained
Update of approaches continues for other agents
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Model Dynamics Explained
B and C are both within A's interaction radius
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Model Dynamics Explained
A's approach was reduced by social influence
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Model Dynamics Explained
Approach is updated immediately
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Model Dynamics Explained
Also B's velocity vector is reduced by social influence
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Model Dynamics Explained
Approach is updated immediately
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Model Dynamics Explained
B and A form a cluster, C leaves interaction areas
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Model Dynamics Explained
Approaches become increasingly more similar
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Model Dynamics Explained
Ground truth is now introduced
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Model Dynamics Explained
Agents are pulled back towards the ground truth ...
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Model Dynamics Explained
… until the velocity of the approaches equalsthe distance from ground truth
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Model Dynamics Explained
Position noise is now introduced
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Model Dynamics Explained
Perturbs the relative position of agents in the cluster
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Model Dynamics Explained
but on average the distance from truth stay the same
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Model Dynamics Explained
Angular noise is now introduced
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Model Dynamics Explained
Perturbs the direction of agents' approaches
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Model Dynamics Explained
Social influence reduce differences in approachesand agents move closer to ground truth
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Structural Variables
Strong signal from ground truth (++) Large interaction radius (++) Angular noise (++) Strong social influence (+)
Fragmentation (-) Clustering (-)
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Correlation Fragmentation and Scientific Progress
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Structural Variables
Social interactions leads to clusters
Clusters move agents closer to truth
Angular noise keeps agents continuously slightly mis-aligned
Diversity of approaches is preserved
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Structural Variables
Social interactions leads to clusters
Clusters move agents closer to truth
Angular noise keeps agents continuously slightly mis-aligned
Diversity of approaches is preserved
Social interactions and peer disagreement are two key mechanisms to promote progress
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Simulation Experiment 2
Randomly assigned agents to c clusters Clusters were placed equally spaced on a circle of
radius d with the ground truth in the center
Varied c to manipulate the degree of fragmentation
Measured time necessary to form consensus on the ground truth (75% within radius 0.05 units)
Varied d to manipulated the degree of progress Measured the average number of clusters at
consensus share 50%
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Simulation Experiment 2
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Simulation Experiment 2
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Simulation Experiment 2
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Simulation Experiment 2
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Simulation Experiment 2
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Simulation Experiment 2
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Simulation Experiment 2
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Simulation Experiment 2
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Simulation Experiment 2
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Fragmentation on Progress
Fragmentation hampers scientific progress
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Progress on Fragmentation
Scientific progress has no effect on fragmentation
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Fragmentation and Progress
Fragmentation slows down scientific progress Progress does not have an effect on
fragmentation
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Fragmentation and Progress
Fragmentation slows down scientific progress Progress does not have an effect on
fragmentation
Both structural variables and fragmentation affect scientific progress
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Fragmentation and Progress
Fragmentation slows down scientific progress Progress does not have an effect on
fragmentation
Both structural variables and fragmentation affect scientific progress
It might be that the structural variables only affect fragmentation, that in turn slows down progress
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Fragmentation and Progress
Fragmentation slows down scientific progress Progress does not have an effect on
fragmentation
Both structural variables and fragmentation affect scientific progress
It might be that the structural variables only affect fragmentation, that in turn slows down progress
To test this hypothesis we performed Baron and Kenny (1986) mediation analysis
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Mediation Analysis Baron and Kenny (1986)
Step 1: Regress progress on structural variables (R, σ, and τ )
Step 2: Regress fragmentation on structural variables (R, σ, and τ )
Step 3: Regress progress on fragmentation and structural variables (R, σ, and τ )
If the statistical effect is smaller in Step 3. than in Step 1. the parameter is partially mediated
If the statistical effect is even insignificant, the parameter is completely mediated
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Mediation Analysis Results
The effect of all structural variables on progress is at least partially mediated by fragmentation
The angular noise parameter σ is completed mediated by fragmentation.
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Mediation Analysis Results
The effect of all structural variables on progress is at least partially mediated by fragmentation
The angular noise parameter σ is completed mediated by fragmentation
Therefore only the length of the radius of influence R, and the strength of attraction to ground truth τ are actually responsible for the correlation between disciplinary fragmentation and scientific progress.
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Research Questions Why are some disciplines more fragmented into
conflicting schools of thoughts than others ? Why do disciplinary fragmentation and limited
scientific progress seem to correlate ?
ETH Zürich | Stefano Balietti | sbalietti@ethz.ch | SOMS Chair of Sociology, Modeling and Simulation
Research Questions Why are some disciplines more fragmented into
conflicting schools of thoughts than others ? Why do disciplinary fragmentation and limited
scientific progress seem to correlate ?
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