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Chapter 9
Verifying and Validating Simulations

Nuno David, Nuno Fachada, and Agostinho C. Rosa

Abstract Verification and validation are two important aspects of model building.
Verification and validation compare models with observations and descriptions of
the problem modelled, which may include other models that have been verified
and validated to some level. However, the use of simulation for modelling social
complexity is very diverse. Often, verification and validation do not refer to
an explicit stage in the simulation development process, but to the modelling
process itself, according to good practices and in a way that grants credibility to
using the simulation for a specific purpose. One cannot consider verification and
validation without considering the purpose of the simulation. This chapter deals
with a comprehensive outline of methodological perspectives and practical uses
of verification and validation. The problem of evaluating simulations is addressed
in four main topics: (1) the meaning of the terms verification and validation in
the context of simulating social complexity; (2) types of validation, as well as
techniques for validating simulations; (3) model replication and comparison as
cornerstones of verification and validation; and (4) the relationship of various
validation types and techniques with different modelling strategies.

Why Read This Chapter?

To help you decide how to check your simulation—both against its antecedent
conceptual models (verification) and external standards such as data or other
simulations (validation)—and in this way help you to establish the credibility of
your simulation. In order to do this the chapter will point out the nature of these
processes, including the variety of ways in which people seek to achieve them.

N. David ( )
DINÂMIA’CET - ISCTE-IUL - Centre for Socioeconomic and Territorial Studies, ISCTE-IUL
Instituto Universitário de Lisboa, Av. das Forças Armadas, 1649-026 Lisboa, Portugal
e-mail: nuno.david@iscte.pt
N. Fachada • A.C. Rosa
Institute for Systems and Robotics (ISR/IST), LARSyS, Instituto Superior Técnico, Av. Rovisco
Pais, 1, 1049-001 Lisboa, Portugal
e-mail: nfachada@laseeb.org; acrosa@laseeb.org

© Springer International Publishing AG 2017 173
B. Edmonds, R. Meyer (eds.), Simulating Social Complexity,
Understanding Complex Systems, https://doi.org/10.1007/978-3-319-66948-9_9