In this chapter the author talked about the “Four-Level Validation Framework”. To be more specific they are “the domain situation”, “visual encoding interaction idiom”, “data/task abstraction” and “algorithm”.
And also we have different angles to attack those different layers. We could do it from bottom-up or we can also be driven by a specific problem. In a real situation the latter is more natural for people like myself because to me data vis is more like a tool to use to solve problems. So instead of investing years of time to researching how to build better lower infrastructure upon which people can build great data vis, I would rather start from a problem, build something that can be used and then figure out how to improve.
The takeaway is that data vis validation also could have a lot of potential traps. A good validation methodology is sometimes crucial and even trickier than figuring out a “solution” (this solution may not even be the thing our user wanted!).