I found this work to be both very interesting and very frustrating. While I broadly agreed with the points the author was making, I felt he often missed the mark in providing a convincing argument. Chapters 1 and 2 did an excellent job setting up the book's premise and diving into the complexities of data settings through the Arnold Arboretum example. Chapter 3, however, completely missed the mark in my mind. It borrowed heavily (and, in some cases, verbatim) from a conference paper Loukissas co-authored by Matthew Battles which makes clear that many of the conclusions presented in Ch 3 as broadly applicable were originally developed only around collection data.
Using the DPLA as an example just doesn't quite fit the claims being made by Loukissas in my eyes, as the data being discussed is a means by which users can access works at their original institutions. His discussion of "data artefacts" as applied to DPLA data falls fairly flat as well. The discussion in Ch 2 does pretty well in providing examples of possible meanings encoded in data artefacts, but Loukissas struggles to do the same in the later chapters, often only claiming such artefacts (like different ways of recording the date, not the most inspiring example) could be important.
His arguments about algorithms and data being inseparable in Ch 4 are also poorly made, in that he completely neglects to discuss (for example) original experimental data and instead only focuses on data created through NLP processes. It's an important case to discuss, yes, but the point that all data should be considered inseparable from algorithms should also have been considered in terms of the human "algorithms" that go into even analog data.
Ch 5 begins an admirable turn towards social justice-focused data initiatives and, along with Ch 6, seems to indicate that Loukissas a key battleground (for lack of a better term) when it comes to the utilization of data. It left me wondering, though, why three out of the four case studies for this book, those covered in Ch 2-4, had little to do with social justice initiatives and were certainly not presented in that sort of framework. If this really was something Loukissas wanted to focus on, I would've liked to see more of a focus on it!