Wherein the authors detail how to get from questions (last chapter) to problems.
What is a problem not? A topic, for one. Why the confusion? "Experienced researchers often talk about their research problem in a shorthand way that seems to describe it just as a topic: I'm working on adult measles, or on early Aztec pots, or on the mating calls of Wyoming elk" (emphasis in orig.).
What is a problem in the research sense of the word? According to the book, it has two parts: a condition/situation and costs. In research (versus life), conditions relate to a lack of knowledge about something, e.g. "How did Latin epics influence Old English poetry?" Costs, in the same vein, are trickier to understand: "If we do not understand _____, we will not understand something yet more significant" (emph. orig.).
This leads to a discussion of pure vs. applied research. The difference lies in the rationale (the third, indirect question in yesterday's post): if it is "in order to understand" or a related word, it counts as pure, whereas if it is "in order to measure" or a related word, it is applied. A common mistake of beginners, say the authors, is to "cobble the solution of a research problem onto the solution of a practical problem." This leads to a weak connection of the question (second question) and rationale (third question). If you want to add the applications of your research to the pure-research results, add a fourth question, significance (e.g. "so that we will know more about doing something...").
Finally, how do practical problems relate to research? The book has a circular diagram, which you can approximate if you twist the following lines text into meeting end-to-end:
Practical problem motivates Research question defines Research problem finds Research answer helps to solve Practical problem...