KNOWING WHICH TYPE OF GRAPH TO USE IN

RESEARCHA foolproof guide to selecting the right image to convey

your important message!

Overview of the Problem:A graph tells a story…

Scatter Plots

Histograms and Bar Graphs

Line Graphs

Box-and-Whisker Plots

Networks

Normality Plots

Residual Plots

Pie Graphs

Stem-and-Leaf Plots

Map Charts

Radar Charts

AN EXAMPLE:

Freshman

Sophomore

Junior

Senior

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DismissedTardyAbsent

• Categorical comparisons• Quick understanding of

relative frequency• Distribution testing• Group comparisons

• <-- Example graph

WHAT ARE THEY GOOD FOR?

Histograms and Bar ChartsHow many of something do I have relative to something else?

AN EXAMPLE:

• Temporal studies• <-- Example graph

• Relational studies with single quantity observations

WHAT ARE THEY GOOD FOR?

Line GraphsHow does a trend change over the course of some other continuous phenomenon?

1995 2000 2005 20100

0.51

1.52

2.53

3.54

4.55

Series 1

Series 1

AN EXAMPLE:

• Monitoring relationships between multiple measurands in an effort to relate them

• Clustering• <-- Example graph

WHAT ARE THEY GOOD FOR?

Scatter PlotsPairing off multiple phenomena…

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10

Salt Content

Salt Content

AN EXAMPLE:

• Finding percentile spreads• Identifying outliers

WHAT ARE THEY GOOD FOR?

Box-and-Whisker PlotPercentile trends and outlying observations

AN EXAMPLE:

• Identifying connections between concepts

• <-- Example graph• Flow charts• Algorithms• Path identification

WHAT ARE THEY GOOD FOR?

NetworksWhat is related to what?

AN EXAMPLE:

• Distribution of a population• Percentages

WHAT ARE THEY GOOD FOR?

Pie graphProportionality of a population

Putouts in No-Hitter

StrikeoutsGround OutsFly OutsOther

AN EXAMPLE:

• Finding a median or mode• Broader distributions

WHAT ARE THEY GOOD FOR?

Stem-and-Leaf PlotsTiered distribution

AN EXAMPLE:

• Multiple comparisons over shared properties

WHAT ARE THEY GOOD FOR?

Radar ChartsWhen you care about too many things…

Carbon Dioxide

Nitrogen

ArgonOxygen

Water Vapor

0

50

100

VenusEarthMars

AN EXAMPLE:

• Similarities/differences based on administrative units

• Regional concerns

WHAT ARE THEY GOOD FOR?

Map ChartsWhere place matters…

AN EXAMPLE:

• Determining the voracity of a model based on distribution of residual values (randomized)

WHAT ARE THEY GOOD FOR?

Residual PlotDo I have the right model type?

AN EXAMPLE:

• Does experimental data conform to the normal distribution

• Note: you can do this for any distribution, but most common for normal distribution

WHAT ARE THEY GOOD FOR?

Normality PlotsDo I have normal data?