Social Media as Windows on the Social Life of the Mind (2007)
This is a programmatic paper, marking out two directions in which the study of social media can contribute to broader problems of social science: understanding cultural evolution and understanding...
Power-law distributions in empirical data (2007)
Clauset, Aaron, Shalizi, Cosma Rohilla, Newman, M. E. J.
Power-law distributions occur in many situations of scientific interest and have significant consequences for our understanding of natural and man-made phenomena. Unfortunately, the empirical...
Maximum Likelihood Estimation for q-Exponential (Tsallis) Distributions (2007)
This expository note describes how to apply the method of maximum likelihood to estimate the parameters of the ``$q$-exponential'' distributions introduced by Tsallis and collaborators. It also...
Discovering Functional Communities in Dynamical Networks (2006)
Shalizi, Cosma Rohilla, Camperi, Marcelo F., Klinkner, Kristina Lisa
Many networks are important because they are substrates for dynamical systems, and their pattern of functional connectivity can itself be dynamic -- they can functionally reorganize, even if their...
Quantifying Self-Organization in Cyclic Cellular Automata (2005)
Shalizi, Cosma Rohilla, Shalizi, Kristina Lisa
Cyclic cellular automata (CCA) are models of excitable media. Started from random initial conditions, they produce several different kinds of spatial structure, depending on their control parameters....
Automatic Filters for the Detection of Coherent Structure in Spatiotemporal Systems (2005)
Shalizi, Cosma Rohilla, Haslinger, Robert, Rouquier, Jean-Baptiste, Klinkner, Kristina Lisa, Moore, Cristopher
Most current methods for identifying coherent structures in spatially-extended systems rely on prior information about the form which those structures take. Here we present two new approaches to...
Measuring Shared Information and Coordinated Activity in Neuronal Networks (2005)
Klinkner, Kristina Lisa, Shalizi, Cosma Rohilla, Camperi, Marcelo F.
Most nervous systems encode information about stimuli in the responding activity of large neuronal networks. This activity often manifests itself as dynamically coordinated sequences of action...
The Backwards Arrow of Time of the Coherently Bayesian Statistical Mechanic (2004)
Many physicists think that the maximum entropy formalism is a straightforward application of Bayesian statistical ideas to statistical mechanics. Some even say that statistical mechanics is just the...
Quantifying Self-Organization with Optimal Predictors (2004)
Shalizi, Cosma Rohilla, Shalizi, Kristina Lisa, Haslinger, Robert
Despite broad interest in self-organizing systems, there are few quantitative, experimentally-applicable criteria for self-organization. The existing criteria all give counter-intuitive results for...
Blind Construction of Optimal Nonlinear Recursive Predictors for Discrete Sequences (2004)
Shalizi, Cosma Rohilla, Shalizi, Kristina Lisa
We present a new method for nonlinear prediction of discrete random sequences under minimal structural assumptions. We give a mathematical construction for optimal predictors of such processes, in...
Quantifying Self-Organization in Cyclic Cellular Automata (2003)
Cosma Rohilla Shalizi, Kristina Lisa Shalizi
Cyclic cellular automata (CCA) are models of excitable media. Started from random initial conditions, they produce several di#erent kinds of spatial structure, depending on their control parameters....
Methods and Techniques of Complex Systems Science: An Overview (2003)
In this chapter, I review the main methods and techniques of complex systems science. As a first step, I distinguish among the broad patterns which recur across complex systems, the topics complex...
Optimal Nonlinear Prediction of Random Fields on Networks (2003)
It is increasingly common to encounter time-varying random fields on networks (metabolic networks, sensor arrays, distributed computing, etc.). This paper considers the problem of optimal, nonlinear...
What Is a Macrostate? Subjective Observations and Objective Dynamics (2003)
Shalizi, Cosma Rohilla, Moore, Cristopher
We consider the question of whether thermodynamic macrostates are objective consequences of dynamics, or subjective reflections of our ignorance of a physical system. We argue that they are both;...
What Is a Macrostate? Subjective Observations and Objective Dynamics (2003)
Shalizi, Cosma Rohilla, Moore, Cristopher
We consider the question of whether thermodynamic macrostates are objective consequences of dynamics, or subjective reflections of our ignorance of a physical system. We argue that they are both;...
An Algorithm for Pattern Discovery in Time Series (2002)
Shalizi, Cosma Rohilla, Shalizi, Kristina Lisa, Crutchfield, James P.
We present a new algorithm for discovering patterns in time series and other sequential data. We exhibit a reliable procedure for building the minimal set of hidden, Markovian states that is...
Symbolic Dynamics for Discrete Adaptive Games (2002)
Shalizi, Cosma Rohilla, Albers, David J.
We use symbolic dynamics to study discrete adaptive games, such as the minority game and the El Farol Bar problem. We show that no such game can have deterministic chaos. We put upper bounds on the...
Thesis (Ph. D.)--University of Wisconsin--Madison, 2001.
Thesis (Ph. D.)--University of Wisconsin--Madison, 2001.
Upper Bound on the Products of Particle Interactions in Cellular Automata (2000)
Hordijk, Wim, Shalizi, Cosma Rohilla, Crutchfield, James P.
Particle-like objects are observed to propagate and interact in many spatially extended dynamical systems. For one of the simplest classes of such systems, one-dimensional cellular automata, we...
Shalizi, Cosma Rohilla, Crutchfield, James P.
Discovering relevant, but possibly hidden, variables is a key step in constructing useful and predictive theories about the natural world. This brief note explains the connections between three...
Pattern Discovery and Computational Mechanics (2000)
this paper we wish to introduce a new term for a related, relatively under-recognized concept, pattern discovery, and a way of tackling such problems, computational mechanics.
Pattern Discovery and Computational Mechanics (2000)
this paper we wish to introduce a new term for a related, relatively under-recognized concept, pattern discovery, and a way of tackling such problems, computational mechanics.
Memes, Mental Epidemiology, and All That: A Critical Review of Models of Cultural Evolution (2000)
Mental Epidemiology, All That, Cosma Rohilla Shalizi, William A. Tozier
Justify our existence in 250 words or less. Contents 1 Introduction 3 1.1 Scope of This Review . . . . . . . . . . . . . . . . . . . . . . . . 3 1.2 Organization of This Review . . . . . . . . . . ....
Pattern Discovery and Computational Mechanics (2000)
Shalizi, Cosma Rohilla, Crutchfield, James P.
Computational mechanics is a method for discovering, describing and quantifying patterns, using tools from statistical physics. It constructs optimal, minimal models of stochastic processes and their...
A Simple Model of the Evolution of Simple Models of Evolution (1999)
Shalizi, Cosma Rohilla, Tozier, William A.
In the spirit of the many recent simple models of evolution inspired by statistical physics, we put forward a simple model of the evolution of such models. Like its objects of study, it is (one...
Computational Mechanics: Pattern and Prediction, Structure and Simplicity (1999)
Shalizi, Cosma Rohilla, Crutchfield, James P.
Computational mechanics, an approach to structural complexity, defines a process's causal states and gives a procedure for finding them. We show that the causal-state representation--an...
Comment on "Simple Measure of Complexity" (1999)
Crutchfield, James P., Feldman, David P., Shalizi, Cosma Rohilla
We critique the measure of complexity introduced by Shiner, Davison, and Landsberg in Ref. [1]. In particular, we point out that it is over-universal, in the sense that it has the same dependence on...
Crutchfield, James P., Shalizi, Cosma Rohilla
Thermodynamic depth is an appealing but flawed structural complexity measure. It depends on a set of macroscopic states for a system, but neither its original introduction by Lloyd and Pagels nor any...
Upper Bound on the Products of Particle Interactions in Cellular Automata
Wim Hordijk, Cosma Rohilla Shalizi, James P. Crutchfield
Particle-like objects are observed to propagate and interact in many spatially extended dynamical systems. For one of the simplest classes of such systems, one-dimensional cellular automata, we...
Cosma Rohilla Shalizi, James P. Crutchfield
Discovering relevant, but possibly hidden, variables is a key step in constructing useful and predictive theories about the natural world. This brief note explains the connections between three...
Pattern Discovery and Computational Mechanics
Cosma Rohilla Shalizi, James P. Crutchfield
Computational mechanics is a method for discovering, describing and quantifying patterns, using tools from statistical physics. It contructs optimal, minimal models of stochastic processes and their...
Computational Mechanics: Pattern and Prediction, Structure and Simplicity
Cosma Rohilla Shalizi, James P. Crutchfield
Computational mechanics, an approach to structural complexity, defines a process's causal states and gives a procedure for finding them. We show that the causal-state representation--an e-machine--is...
Comments on ``Simple Measure for Complexity''
James P. Crutchfield, David P. Feldman, Cosma Rohilla Shalizi
We critique the measure of complexity introduced by Shiner, Davison, and Landsberg in Ref. [1]. In particular, we point out that it is over-universal, in the sense that it has the same dependence on...
Thermodynamic Depth of Causal States: When Paddling Around in Occam's Pool Shallowness Is a Virtue
James P. Crutchfield, Cosma Rohilla Shalizi
Thermodynamic depth is an appealing but flawed complexity measure. It depends on a set of macroscopic states for a system, but neither its original introduction by Lloyd and Pagels nor any follow-up...