Lecture 32 — The Whole Toolbox: Capstone Cases
Position in the course
This is lecture 32 of 32. It belongs to the course arc described in the course outline and uses the standard interactive case method: display, attempt (5 minutes), discuss, reveal, name the technique.
This lecture runs as the capstone session (time-capped attempts with live defence; see the timing plan), not the standard four-case rhythm.
Learning objectives
- Integrate the full toolbox on unfamiliar problems
- Communicate a solution: model, algorithm, tests
- Justify trade-offs under time pressure
By the end of this lecture students can do all three under time pressure, which is what the four cases exercise.
Prerequisite knowledge
Before this lecture: Lectures 01–31 — the full toolbox
Assumed fluencies:
- all techniques at readiness level
Preparation task: Re-attempt the mid-course challenge cup (lecture 16) and compare with your old plan.
Detailed topic outline
Core (mandatory):
- integration under a time cap
- technique selection from a brief
- the plan-first discipline at capstone level
- defending choices in a live Q&A
Extension (optional enrichment):
- course-level retrospective
- what to learn next
Case sequence
| Case | Title | Difficulty |
|---|---|---|
| cs-125 | The Library Robot | Beginner |
| cs-126 | The Open-Day Planner | Foundational |
| cs-127 | The Data Clinic | Intermediate |
| cs-128 | The 20-Minute Final | Advanced |
Display each case full-screen from the student page (cases cs-125–cs-128); instructor pages cs-125–cs-128 under case-studies/instructor/ hold the full solutions, reveal guides, and discussion prompts.
Timing plan (120 minutes)
Format: capstone session — deliberately not the standard case rhythm.
| Minutes | Segment |
|---|---|
| 0–10 | Framing: what the capstone certifies; how defence works |
| 10–15 | Brief (cs-125–cs-128): rules, time caps, deliverables |
| 15–25 | Planning: written plans, techniques named, no code yet |
| 25–55 | Attempt 1: cs-125 under the clock |
| 55–60 | Break |
| 60–90 | Attempt 2 (cs-128): the capstone case, full integration |
| 90–110 | Live defence: 90-second plan presentations; the room asks falsifying questions |
| 110–120 | Course retrospective map, what-to-learn-next, exit questions |
Timing flexes with the room: if a case ignites the class, let the discussion run and compress the synthesis; if the attempts stall, harvest partial attempts rather than extending the clock.
Worked examples
- cs-127 data clinic: a full pipeline — audit, clean, analyse, report — assembled live from named lecture techniques.
Instructor demonstration to open the lecture: Run the 20-minute final (cs-128) yourself, badly, on purpose: the class diagnoses which plan mistakes cost the most.
Classroom activities
| # | Activity | Minutes | Format and prompt |
|---|---|---|---|
| 1 | Toolbox auction | 6 | Teams allocate their 20 minutes across four cases and must justify the split. |
| 2 | Live plan defence | 10 | cs-125 plans presented in 90 seconds each; the room asks one falsifying question per plan. |
| 3 | Course retrospective map | 8 | The 32 lectures are pinned on a wall map of techniques; each student marks their growth edge. |
Board plan
- Left third: the case statement, kept visible for the whole cycle.
- Middle third: students' contrasting attempts (two maximum).
- Right third: the reference trace or table, revealed last.
- Bottom strip, written during the cycle: the name of the technique and the one-line invariant or rule this case taught.
Instructor explanation notes
Reading the room. The capstone is a rehearsal of professional practice: briefs, time caps, live defence. Grade the plan and the defence as heavily as the answer.
Running the reveal. Leave 15 minutes for the retrospective map and the what-next pointers — the course's closing argument is that the toolbox is now theirs.
Lecture focus. One sentence to repeat verbatim: Under a cap: plan first, defend live, integrate everything.
Common misconceptions
- Abandoning the plan at the first obstacle instead of adapting it.
- Spending the whole cap polishing one case and abandoning the rest.
- Defending choices with 'it works' instead of trade-offs.
- Leaving the retrospective to memory instead of writing the map.
Each case's instructor page lists the specific wrong turn to expect; the reveal should address it by name.
Student practice exercises
Core:
- Produce a 10-line integration plan for the library robot (cs-125) naming three techniques.
- Time-capped run: cs-126 in 18 minutes, plan first, then exchange plans for peer review.
- Write the data-clinic (cs-127) pipeline sketch: audit → clean → analyse → report.
Enrichment (optional):
- Write the capstone case you wish had been in the course, with solution sketch.
- Map your five strongest and five weakest techniques; set a study plan.
Formative assessment
Exit questions (choose one; answer on a card in 60 seconds):
- What did the plan-first discipline buy you today? Expected: a defensible partial answer under a hard cap
- Name two cases where two techniques had to combine. Expected: cs-125 (graphs + greedy), cs-127 (cleaning + statistics)
- What is your next technique to strengthen, and where will you practise it? Expected: student's own map from the retrospective
Cards are skimmed before the next lecture; three answers become the framing. Persistent wrong answers route students to the review stations of lecture 16 or to office hours.
Homework and preparation
- Before: skim the four student pages; attempt case 1 on paper.
- After: write a five-line pseudocode solution for any case you did not finish in class; bring one question to the next lecture.
- Enrichment (optional): the stretch question on each case page.
Learning-outcome mapping
- Primary outcomes: LO1, LO2, LO10 — Capstone integration, defence, and strategy selection.
- Coverage details: learning outcomes; assessed via the scheduled quizzes, labs, assignments, and term project in the assessment plan.
Differentiation
- Beginners: aim for a correct plan in pseudocode; Python is optional.
- Intermediate: full Python on cases 1–3, plan on case 4.
- Advanced students: finish early, then answer "what breaks at 10x scale?" and present the alternative-approach bullet from the instructor page.
- Everyone: state one assumption out loud before writing anything.