John H. Holland, Facetwise Models, and Economy of Thought

Noted complex adaptive system researcher John H. Holland now receives acclaim from many quarters, but it is important to understand that this man and his ideas have been controversial since the beginning of his career. Genetic algorithms (GAs) were ignored or disparaged throughout the 1960s and 1970s, and even now, as these and his other ideas receive worldwide recognition in broad outline, the specifics of his mode of thought and insight are rejected by many who claim to embrace his key insights. This is a mistake. I have known John Holland for 23 years, and I have learned many things from him, but a critical influence has been his style of thought, in particular, his style of modeling. John has an uncanny knack of getting to the heart of a matter through the construction of what I call little models. Sometimes these models are verbal, sometimes they are mathematical, but they almost always shed a great deal of light on some nagging question in the analysis and design of complex systems. In this chapter, I propose to briefly explore John Holland's style of little modeling, and better understand its nature, its essence, and why some of those who embrace the broad outlines of his teaching have been slow to embrace the details of his modeling and the style of his thought. The exploration begins by recalling my own first impressions of John Holland and his style of thought, impressions made 23 years ago in a classroom in Ann Arbor, Michigan. It continues with a case study in Holland-style facetwise model building in constructing a takeover time model. It continues by integrating the takeover time model with a model of innovation on dimensional grounds. Finally, the Hollandian mode of model building is placed on intellectual terra firma with an economic argument, suggesting that the costs of modeling or thought must be weighed in relation to the model's benefits in understanding or designing a complex system.