Lc08: Distribution Charts

What are criteria that a distribution can be judged on?

center, spread, shape, unusual values

Histogram

Shows the distribution of one quantitative variable

• Bins group observations into numerical intervals

What does the x-axis in a Histogram show?

the intervals in numeric order

What does the y-axis in a Histogram show?

the frequency, percentage, or density

Why do Adjacent Bins normally touch in a Histogram?

Because the numerical scale is continuous

What do Narrow Bins reveal in a Histogram?

More detail

What do Wider Bins produce in a Histogram?

a smoother summary

Boxplots / Box-and-Whisker Plot

Useful for detecting potential outliers and identifying the spread and skewness of a dataset

What do the Whiskers define in a Boxplot?

A boundary to detect potential outliers

How are Outliers plotted on Boxplots?

As individual points beyond the whiskers

What does each dot represent in a Strip Plot?

one observation of a quantitative variable

What do separate strips compare in a Strip Plot?

Distributions across categories

What to look for in Strip Plot?

Clusters, spread, gaps, and unusual values

When to use a neutral color in a Strip Plot?

When color adds no useful info

When to use a distinct color in a Strip Plot?

For a small number of meaningful groups

When to use a contrasting color in a Strip Plot?

to highlight losses or another condition

Main limitation of Histogram

Bin choices affect the visible pattern

Main limitation of Boxplot

Clusters and exact values can be hidden

Main limitation of Strip Plot

Dots can overlap