Data Driven Decision Making

Part II

Visual Evidence: From Charts to Dashboards

Charts that answer, not decorate

This part is about visual argument: turning a clean dataset into a chart that answers a named business question without quietly overclaiming. Chapter 3 supplies the grammar, matching each visual family to the decision it serves and treating a dashboard as a structured memo from executive question to recommended action. Chapter 4 sharpens the craft — a chart's first choice is its baseline, confidence intervals describe variation rather than cause, and the honest endpoint of any dashboard is the next test to run. Together they move the reader from picking a chart type to defending a one-page board memo with its limits stated out loud.

2 chapters · 9 articles

What you’ll learn

  • Map a business question to the right visual family — distribution, comparison, time, relationship, geography, or uncertainty
  • Structure a dashboard as a memo: KPI, trend, breakdown, drilldown, and a recommended action
  • Choose the baseline and index a series before choosing color, so comparisons read honestly
  • Read confidence intervals and small multiples as descriptions of variation, not claims of causation
  • Assemble grain, joins, metrics, and reshaping into a one-page board memo that names its own causal limits

Chapters in this part

Chapter 3Chart Grammar for Business Questions

Pick the chart from the question, not the question from the chart — and the definition underneath the metric matters more than the metric.

StudiosNYC Airbnb: A Listings AtlasIndustry Ad Spend Explorer
Chapter 4Comparison, Uncertainty, and Dashboards

Every chart is a comparison — name the baseline, show the spread, and end on a decision, not a pattern.

StudiosFast-Food Share of Wallet: C…An Index AutopsyNYC Taxi/Ride-Hail: Uber & L…The Coefficient ZooThe Slope Factory

Interactive studios

Hands-on studios paired with this part’s chapters — each opens in a new tab.

RestaurantsFast-Food Share of Wallet: COVID ImpactHow did the pandemic redraw where consumers spent their fast-food dollars? A share-of-wallet dashboard that benchmarks chains against the category through the shock and recovery.MarketplacesNYC Airbnb: A Listings AtlasExplore tens of thousands of NYC listings by neighborhood, room type, and price — a worked example of how exploratory views turn a raw marketplace dump into a map of where supply and money actually sit.Methods, AI & DataAn Index AutopsyWe rebuilt a deprivation index from scratch with PCA — no housing costs — and compared it to the canonical ADI. They agree on the gradient and disagree violently about New York.AdvertisingIndustry Ad Spend ExplorerExplore 2018-2022 advertising spend by industry group, advertiser, and media type, with a Covid-era lens on budget shocks, recovery, and media mix shifts.MobilityNYC Taxi/Ride-Hail: Uber & Lyft at the COVID EmergencyTrace Uber and Lyft rides across NYC pickup zones as demand breaks around the March 2020 emergency declaration, then compare the late-April floor by borough and zone.Methods, AI & DataThe Coefficient ZooFifty-one regressions per health behavior: what doubling a neighborhoodMethods, AI & DataThe Slope FactoryWe fit the deprivation–life-expectancy regression separately in 266 American metros. Every single slope came back negative. Many small models, one law.

Featured data stories

Interactive D3 pieces from the gallery that put this part’s ideas to work — each opens in a new tab.

Polarization & Public OpinionThe Great Divergence: Teen Political IdentityReligion & BeliefThe Shape of Belief: World Religious CompositionElections & VotingPresidential Election Atlas: 1976-2024Demographics & SocietyFifty Years of American EveningsPolarization & Public OpinionAmerica Didn’t Wait for the Unsorted to Die — They SwitchedElections & VotingAmerica Now Holds One Election, Not 3,100Polarization & Public OpinionAmericans Didn’t Fall in Love With Their Party. They Learned to Despise the Other One.Polarization & Public OpinionOne Country, Two TimelinesPolarization & Public OpinionPartisans Finally Got ConstraintElections & VotingRich Counties Still Lean Republican Once You Control for DiplomasHappiness & Well-BeingSmiles and Ladders: Where Good Days and Good Lives Come ApartInequality & MobilityThe Born-Rich PremiumInequality & MobilityThe Company You KeepDemographics & SocietyThe Eight AmericasHealth & MortalityThe Flat LineElections & VotingThe Flip Counties Felt It FirstPolarization & Public OpinionThe Gen Z Gender War Is Real, New — and Half the Size You’ve HeardPolarization & Public OpinionThe Great Sorting: How Americans Re-Sorted Into Two PartiesPolarization & Public OpinionThe Income Ladder FlippedHappiness & Well-BeingThe Loneliness GeographyHappiness & Well-BeingThe Plateau Is in the Tail, Not the MeanElections & VotingThe Purple County Is a LieHappiness & Well-BeingThe Stress Decade: How the World's Days Got Heavier, 2008–2019Health & MortalityWhere It Is Deadliest to Be PoorHealth & MortalityWithin Reach: Teen Drug AvailabilityPolarization & Public OpinionYour County Can’t Change Your Mind: Party Beats Place 8-to-1Consumer & Household FinanceDoing Okay: American Financial Wellbeing