cs-112 — The Dashboard Defence
| Field | Value |
|---|---|
| id | cs-112 |
| difficulty | Advanced |
| topics | summary design, ethics |
| lecture | lecture-28 |
| estimated time | 5-minute attempt + 10-minute discussion |
| prerequisites | functions, dictionaries, and earlier algorithmic patterns |
| objective | design the algorithm, verify it on edges, and argue correctness or trade-offs |
| solution | held by the instructor; discussed after the attempt |
Problem
A dashboard shows 'average response time 2s'. Find three honest-but-misleading framings and redesign the summary. Communication as a design problem.
Your deliverable is the stated assumptions, the corrected chart or summary described precisely, and one sentence defending it to the stakeholder who liked the old one. If the problem is ambiguous anywhere, state the assumption you are making and carry on — a stated assumption is part of a good answer.
Examples
- Input: dashboard: 'average response time 2s' hiding a bimodal 0.2s/8s split
- Output: redesigns: median + p95, separate fast/slow paths, distribution sparkline - each tells the truth the mean hides
Solve for the worked instance first. Then ask what would change if one number, name, or condition were replaced by something stranger.
What to notice
- A summary misleads when two different realities produce the same number. Find the split, then show it.
- Writing the rules IS the solution; code is transcription.
- Every assumption is a place where two good answers can differ.
Discussion starter
After the solution is revealed, the class spends five minutes on this prompt: "Which assumption would you attack first if you had to argue the other side?"
Constraints and assumptions
- Difficulty: Advanced (functions, dictionaries, and algorithmic reasoning assumed).
- Topics: summary design, ethics.
- Classroom-scale inputs unless the problem says otherwise.
- Time-box: about five minutes for a defensible plan; a complete solution may take longer and that is expected - state where you would resume.
- Optional stretch (not required): describe an alternative approach and say when it beats the obvious one.
Hints and extension
- First nudge: identify the pattern the worked instance uses before computing anything.
- If stuck after three minutes, write the input/output line you expect and trace the smallest example by hand.
- After the reveal, attempt the extension below before the next lecture.
- Extension challenge: Write the two honest headlines for this summary and their audiences.