Unit 7 · Moderate
Turning an analysis into something another person can read and trust. The technical content is small; the judgement about honest presentation is the substance.
What a strong answer looks like
A strong Unit 7 answer justifies the chart type from the question being asked and states what the axes and scale do to the reader.
Know
The chart follows the question. Comparison across categories suits bars, change over time suits lines, and relationships between two numeric variables suit scatter.
Apply
State the question first, then pick the form that answers it directly.
Watch out
Choosing a chart because it looks impressive rather than because it answers the question.
Study move
Write three questions about one dataset and pick a different appropriate chart for each.
Know
A chart without labelled axes and units is not interpretable. A truncated axis exaggerates differences and must be disclosed.
Apply
Label both axes with units, and start a bar chart axis at zero unless there is a stated reason not to.
Watch out
A truncated axis making a small difference look dramatic, which misleads even when unintended.
Study move
Plot the same data with a zero baseline and a truncated one and describe the difference in impression.
Know
Presentation choices carry claims. Aggregating away variation, hiding sample sizes, or picking a flattering range are all arguments made silently.
Apply
Show the spread, not just the average, and report how many observations each summary rests on.
Watch out
Reporting a mean for a tiny group beside one for a large group without noting the difference.
Study move
Take a summary chart and add the information a sceptical reader would ask for.
Know
A visualisation needs a sentence saying what the reader should take from it, and a good one states the limits as well as the finding.
Apply
Write one sentence of finding and one of caveat beside every chart you present.
Watch out
Presenting a correlation with language that implies causation.
Study move
Write the finding and caveat sentences for a chart you have already made.
Connections and techniques that receive extra attention in this unit.
Related topics some schools attach to this unit and others leave out. Covered on request rather than assumed.
Modeling drill
Produce one chart answering a stated question about a dataset, with labelled axes, visible sample sizes, and a two-sentence interpretation.
