The ODD Protocol for Describing Agent-Based and Other Simulation Models: A Second Update to Improve Clarity, Replication, and Structural Realism

Abstract

The Overview, Design concepts and Details (ODD) protocol for describing Individual-and Agent-Based Models (ABMs) is now widely accepted and used to document such models in journal articles. As a standardized document for providing a consistent, logical and readable account of the structure and dynamics of ABMs, some research groups also find it useful as a workflow for model design. Even so, there are still limitations to ODD that obstruct its more widespread adoption. Such limitations are discussed and addressed in this paper: the limited availability of guidance on how to use ODD; the length of ODD documents; limitations of ODD for highly complex models; lack of su icient details of many ODDs to enable reimplementation without access to the model code; and the lack of provision for sections in the document structure covering model design rationale, the model's underlying narrative, and the means by which the model's fitness for purpose is evaluated. We document the steps we have taken to provide better guidance on: structuring complex ODDs and an ODD summary for inclusion in a journal article (with full details in supplementary material; Table ); using ODD to JASSS, ( ) , http://jasss.soc.surrey.ac.uk/ / / .html Doi: . /jasss.point readers to relevant sections of the model code; update the document structure to include sections on model rationale and evaluation. We also further advocate the need for standard descriptions of simulation experiments and argue that ODD can in principle be used for any type of simulation model. Thereby ODD would provide a lingua franca for simulation modelling.

Three questions to ask before using model outputs for decision support

“…They provide a common language for modelers and decision makers. They help to evaluate models and take them into account according to their purpose and evidence (TRACE: TRAnsparent and Comprehensive model "Evaludation" 8 ); ODD: overview, design concepts, details 10 ).…”

Epidemiology of age-dependent prevalence of Bovine Herpes Virus Type 1 (BoHV-1) in dairy herds with and without vaccination

“…A stochastic, individual-based, herd-level simulation model of BoHV-1 infection was developed to demonstrate the dynamics of age-dependent patterns of seroprevalence in BoHV-1 seropositive herds and provide a qualitative comparison with those of our serology data (Dataset A). The documentation of the model follows the ODD protocol (overview, design concepts, and details); [26][27][28] and is provided in the supplementary material (see Additional file 1).…”

A Model to Illustrate the Potential Pairing of Animal Biotelemetry with Individual-Based Modeling

“…Eight of eleven individual-based model design concepts identi ed in (11) appear in this model, including basic principles, emergence, adaptation, objectives, prediction, sensing, stochasticity, and observation. Learning, interaction, and collectives are not included.…”

“…3. Smolts are assumed to begin a directed northward migration shortly after reaching the ocean, an assumption that is strongly supported by decades of U.S. and Canadian coastal trawl surveys (59), Grimm et al (11) distinguish adaptive behaviors as direct or indirect objective-seeking. In the former, individuals make decisions based on alternatives ranked according to some measure of how they contribute to meeting an objective.…”

“…Orientation toward habitat, to maximize growth (MaxGro smolts) or minimize opposing current (MinCur smolts), are direct objective-seeking behaviors whose proximate objective is to grow rapidly or speed through a predator-rich region, respectively, and ultimately to survive and return to reproduce. Orientation along these gradients is an implicit prediction per (11) and there is no explicit prediction in the model.…”