New Mexico Computer Science for All Agent-based modeling By Irene Lee December 27, 2012

Agent-based Modeling of Complex Adaptive Systems Using agent-based modeling (ABM) tools, we are able to model complex adaptive systems. An example: termites model The model consists of agents, an environ- ment, and interactions between agents and environment. The system is adaptive and changes over time. ABM generates “emergent” patterns. Agent-based modeling: a tool for studying complex adaptive systems

Agent-based modeling paradigm The “Observer”– instantiates the world The “Turtles”– the agents The “Patches” – the environment

Agent based modeling phases Setup– instantiation of world Runtime loop – the agents put into motion. Exit

Agent-based modeling Abstractions Agents with rules Environment or space in which they exist Time

NetLogo is a programming language

Creating Computer Models with NetLogo

Modeling and Computational Science A model is a representation of the interaction of real-world objects in a complex system. The goal is to gain an understanding of how the model’s results relate to real-world phenomena. Random factors built into the model and variables changed by the user cause different results to be generated when the model is run repeatedly.

Idea Models Idea Models e.g. Model of Predator and Prey e.g. Model of Predator and Prey Minimal Models for Systems Minimal Models for Systems e.g. Model of Wolves and Caribou e.g. Model of Wolves and Caribou Systems Models / Large scale ? Systems Models / Large scale ? e.g. Model of every Wolf and Caribou in 5 square mile section of Yellowstone e.g. Model of every Wolf and Caribou in 5 square mile section of Yellowstone *This classification scheme was proposed by J. Roughgarden. Increasing complexity, detail and specificity * Model Classification Scheme *

learning about models and modeling conduct experiments by changing variables, collecting data, and analyzing results. deconstruct models into agents, behaviors, environment, and interactions. develop expertise in evaluating models coding/decoding skills and sustained reasoning Abstraction of a real-world problem into a computer model suitable for testing hypotheses. Evaluation of model, choice of assumptions, and findings. A Progression for Learning about Modeling Use Modify Create Use Modify Create

Scientific Inquiry / Critical thinking skills Students as creators and young researchers Understanding the use of computers in STEM fields Preparation for future endeavors in computing Building an understanding of complex systems Preparation for STEM futures

Concepts that modelers must understand to deconstruct and eventually write agent based models are: 1) states 2) variables 3) data structures 4) rules, logic and control structures, Boolean operations 5) iteration and recursion 6) functions, procedures, subroutines 7) syntax of programming 8) interface design 9) data analysis (import/export and plot data) 10) parallelism. Preparation for Computer Science