Exercises: Evaluate Reports Based on Data
Each report below makes a claim from data. Work through the four lenses: (1) the sample — who was studied and how were they chosen; (2) the design — does it license association only, or causation; (3) the uncertainty — is a sample size, margin of error, or significance disclosed; and (4) the display — is any graph honest. Write explanation answers in complete sentences. A causal verb ("causes," "raises") needs a randomized experiment; an observational study supports association only.
Warm-Up: Taking a Report Apart
These problems review the parts of a report and the IC vocabulary you already know.
The four evaluation lenses are sampling, design, uncertainty, and display. Match each report weakness to its lens. "The report never says how many people were surveyed" is a problem with the ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ lens. "A bar chart's y-axis starts at 90 instead of 0" is a problem with the ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ lens. (Use one word for each: sampling, design, uncertainty, or display.)