This chapter provides a general introduction of network modeling in
psychometrics. The chapter starts with an introduction to the statistical model
formulation of pairwise Markov random fields (PMRF), followed by an
introduction of the PMRF suitable for binary data: the Ising model. The Ising
model is a model used in ferromagnetism to explain phase transitions in a field
of particles. Following the description of the Ising model in statistical
physics, the chapter continues to show that the Ising model is closely related
to models used in psychometrics. The Ising model can be shown to be equivalent
to certain kinds of logistic regression models, loglinear models and
multi-dimensional item response theory (MIRT) models. The equivalence between
the Ising model and the MIRT model puts standard psychometrics in a new light
and leads to a strikingly different interpretation of well-known latent
variable models. The chapter gives an overview of methods that can be used to
estimate the Ising model, and concludes with a discussion on the interpretation
of latent variables given the equivalence between the Ising model and MIRT.Comment: In Irwing, P., Hughes, D., and Booth, T. (2018). The Wiley Handbook
of Psychometric Testing, 2 Volume Set: A Multidisciplinary Reference on
Survey, Scale and Test Development. New York: Wile