ASSERT and Orlando

Orlando, Florida satellite image, and Green Swamp Wilderness Preserve satellite image, showing the same land areas. The images' centers are 40 miles from each other.

How did what we now call Orlando, Florida transform from former Seminole Indian territory with fewer than one hundred permanent settlements in 1885 to a city of more than 285,000 people in 2019? Of course, the simple answer is a combination of human migration and reproduction, but the more compelling answer is visual: less than five generations ago, Orlando's 114 square miles were all wetlands and some 31 lakes, and now they are a jungle of asphalt, concrete, human residences, businesses, and massive amusement parks. The images above illustrate the change starkly. Green Swamp Wilderness Preserve speckled with lakes is the Orlando of 135 years ago.

The question above is my application of Bill Ferster's Interactive Visualization: Insight Through Inquiry, specifically his ASSERT model:

Ask a question
Search for data
Structure the information
Envision ways to answer
Represent the data
Tell a meaningful story

Ferster's work is a powerful synthesis of more than 500 years of tradecraft in visualization, if one starts with Leonardo da Vinci's Vitruvian Man circa 1490. I must pay tribute to the design excellence of his introductory chapter: somewhere on page 37 my fascination with his historical survey of visualization theory and practice gave way to impatience--is he going to digest all that for his readers into a practical application? It was not even 200 more words of reading after thinking this before he introduced his ASSERT model, and my confidence in it is immeasurably greater having read his stimulating establishment of his bona fide expertise. Bluntly, I would not have the perseverance to read through (or even skim and distill) the score of theoretical works on data visualization that Ferster summarizes, but I am grateful that he did.

Asking my question is easy, but the search for data is where the challenge begins. Based on a initial foray into the historical maps at the Library of Congress and the David Rumsey Historical Map Collection, I am fairly confident that I will be able to start with several dozen maps starting with mid-19th century military surveys and broadly trace out the city's development. Then come the devilish details: what level of detail do I want to shoot for? How comfortable am I with distortions for simplicity of visualization, e.g., animating road development at a constant rate when there were almost certainly delays of various kinds? In the next week or two, I hope to identify my primary sources and the ways I will structure them so as to make them manageable. I'm already envisioning ways I will represent the data, mainly through an animation that connects the historical maps to each other in a transparent way (making the potential distortions recognizable), and then perhaps too ambitiously I hope to provide a zoom feature and an easily adjusted timeline slider.

I've already learned something surprising that will make it into the story: Orlando's population growth is not nearly as much the story of NASA and the Walt Disney Corporation as one would think. Indeed, a line graph of the city's population over time shows no unmistakable spikes in the 1960s and 1970s--just a continuation of a more or less steady natural increase. Hopefully, through the construction of an interactive visualization of the city's growth and development, I will recognize more about the forces that have driven Orlando's birth and transformation geographically over the past 135 years.

Questions for Dr. Ferster:

1. What practical visualization software is the best 'gateway drug' for historians who are interested in but intimidated by interactive visualizations?
2. Even 19th century positivist historians wanted readers to interact with their texts in meaningful ways--how qualitatively different are modern historians' interactive visualizations from traditional prose-text scholarship?