DEEP books vs. ineffective problem-solvers For a problem-solver to be recommended frequently enough to endure and grow, it requires four qualities, represented with the acronym DEEP:[4] Desirable — readers want what it is promising (Chapters 2 and 3) Effective — it delivers real results for the average reader (Chapters 3 and 5-6) Engaging — it’s front-loaded with value, has high value-per-page, and feels rewarding to read (Chapter 4) Polished — it is professionally written and presented (Appendix)
