Exercise 2: Which Workflow Stage Is Out of Scope, and Why Explore Gets the Most Chapters — Possible Solution ==================================================================== THE FIVE STAGES, PER THIS CHAPTER ------------------------------ Per this chapter's own flow-steps: Collect, Clean, Explore, Model, Communicate — with Model marked visually and explicitly as "deliberately out of scope for this course — this is ml1's entire job, start to finish." WHY MODEL IS THE STAGE MARKED OUT OF SCOPE ------------------------------ This directly matches this chapter's own earlier distinction between data science (the broad discipline) and machine learning (model- building specifically). Since this course scopes itself around data science minus machine learning, and per the chapter "Model" is defined as "build a predictive or classification model" — exactly the definition given for machine learning earlier in the chapter — it follows necessarily that Model is the one stage this course excludes. WHICH STAGE GETS THE MOST CHAPTERS, PER THIS CHAPTER'S OWN TABLE ------------------------------ Per this chapter, "Explore... Covered in ds1-5 through ds1-9 — the largest share of this course by chapter count, because it's the largest share of real data science work." Counting the chapters explicitly named: ds1-5, ds1-6, ds1-7, ds1-8, and ds1-9 — five chapters devoted to the Explore stage alone, out of the course's own ten total chapters (not counting ds1-1's own introductory chapter or ds1-10's capstone). WHY THIS ALLOCATION MATCHES THE CHAPTER'S OWN STATED REASONING ------------------------------ The chapter states its reasoning for this allocation directly: chapter count tracks how much real, everyday data science work each stage actually represents, not an arbitrary or evenly-spread division. Given the chapter's own earlier warn-box — "a huge amount of real, valuable data science work... happens before any model gets built" — it follows that a course scoped specifically around the pre-modeling stages would naturally spend most of its length on the stage (Explore) that represents the largest share of that pre-modeling work, exactly as the chapter states outright rather than leaving the reader to infer it. WHY THIS WORKS AS AN ANSWER ------------------------------ It identifies Model as the excluded stage using the chapter's own explicit marking and definitional overlap with "machine learning," counts the specific chapters the chapter itself assigns to Explore, and ties the resulting five-chapter concentration directly back to the chapter's own stated rationale (chapter count reflecting real-world work distribution) rather than treating the allocation as arbitrary.