L01.md

id	course-da-visualization-l01
type	course
title	Challenge 01: A chart is packaged evidence
summary	Say what claim each required PNG makes before writing code — the JSON summary is the auditable layer.
lang	en-US
content_version	1
status	reviewed
reviewed_on	2026-09-12
hints	title body What this checkpoint tests Charts as packaged evidence: before coding, say what claim each required PNG makes — `revenue_by_region` claims region totals, `daily_revenue` claims the trend, `revenue_histogram` claims the distribution. title body Claim before pixels A chart whose numbers are wrong is a lie with good typography — the JSON summary is the auditable layer the PNG must match. title body When you are done You can state the three claims and which aggregation feeds each.

Challenge 01: A chart is packaged evidence

Gate: self-attested · Points: 10

Every chart is a claim about numbers. Before writing code, say out loud what each of the three required charts claims:

• revenue_by_region.png claims: "region totals are X, Y, Z."
• daily_revenue.png claims: "the daily series looks like this."
• revenue_histogram.png claims: "row-level revenue is distributed like this."

If the claim is wrong, a beautiful chart is worse than no chart.

Checkpoint: you can state the claim behind each chart. Self-attested; record via python verify.py.