INTRO TO DATA VIZ

Getting your hands dirty

@bayreporta

CONSIDERATIONS

Tell one story.

Think less, understand more.

Respect the chart.

Know your audience.

TELL ONE STORY

What is the most important information you're trying to convey?

WHAT'S THE STORY?

WHAT'S THE STORY?

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Source: New York Times

WHAT'S THE STORY?

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Source: Globe and Mail

WHAT'S THE STORY?

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Source: KQED

THINK LESS, UNDERSTAND MORE

Consider data literacy.

Accuracy.

Avoid gimmick.

WTF?

CONSIDER DATA LITERACY

Source: UK Guardian

ACCURACY

Source: Fox News

AVOID GIMMICK

Source: Financial Times

WTF?

Source: Canadian Broadcast Corporation

KNOW YOUR AUDIENCE

General or niche?

Desktop vs. mobile?

Data literacy, again.

GENERAL DESIGN TIPS

Label sparingly.

A Minimalist's Guide

Mute gridlines and axis lines.

Think critically about color and shading.

Don't misrepresent the data.

Let the data determine the best chart.

CHARTS!

Ways to visualize data

Table

Line Chart

Area Chart

Pie Chart

Bar Chart

Stacked Bar Chart

Scatter Plot Chart

Bubble Chart

TABLE

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Display large amounts of data.

Allows for exploration of data.

Search functions can assist with queries.

Not Pretty, But Useful

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Tips and Considerations

Shade columns for emphasis.

Search functions to filter data.

Strategic gridlines.

Logical sorting.

Align text left, align numbers right.

TABLE

Great Search, Random Emphasis

Source: Bay Area News Group

TABLE

A Different Take

Source: Center for Investigative Reporting

TABLE

Simple Tools

Google Charts

DataWrapper

LINE CHART

Don't Trend on Me

Change over time, especially small changes.

Works well with one or more variables.

Relationship between time and data.

LINE CHART

Tips and Considerations

Be aware of the baseline.

Use color and shading strategically.

Label lines directly.

Clear axis ticks.

LINE CHART

Clean, Strategic Color Use

Source: Mother Jones

LINE CHART

Baseline and Axis Distortion

Source: Fox News

LINE CHART

Simple Tools

Google Charts

DataWrapper

DataVisual

AREA CHART

Line Chart Plus

Comparing parts of a whole over time.

Where lines show rate, fill shows substance. 

Shows cumulation.

AREA CHART

Tips and Considerations

Avoid visual overlap.

Best at showing vast differences.

When showing cumulation, clarity is required.

AREA CHART

Cumulation or Proportion?

Source: christina29 info blog

AREA CHART

Simple Tools

Google Charts

DataVisual

PIE CHART

Not Just For Eating

Comparing parts of the whole.

Best when data is categorical.

Even better when showing distinct differences.

PIE CHART

Tips and Considerations

Avoid 3D and donut variants.

Restrict variables to a few.

Never compare different pie charts.

Largest segment top right, then work counter-clockwise.

PIE CHART

Clear Difference Between Variables

Source: Joystick Tales

PIE CHART

NEVER DO THIS!!!!

Source: THINK Magazine

DONUT CHART

Great for Eating, Bad for Visualization

Source: Business Week

PIE CHART

Simple Tools

Google Charts

DataWrapper

DataVisual

BAR CHART

Rectangles Are Cool

Good for showing large changes over time.

Easy to compare differences.

Best at ranking data.

Histogram variant for distribution.

BAR CHART

Tips and Considerations

Watch those baselines!

If ranking, sort by largest to smallest.

Avoid narrow bars and mind the gap.

Avoid 3D.

BAR CHART

Ranked Bars

Source: 538

BAR CHART

Comparing Different Variables

Source: New York Times

BAR CHART

What's Going On Here?

Source: Perceptual Edge

BAR CHART

Simple Tools

Google Charts

DataVisual (Column only)

DataWrapper

STACKED BAR CHART

Stacked Rectangles Are Cooler

Easily compare across bars.

Comparing parts of a whole.

Percentage or Proportion.

Tips and Considerations

Largest value first.

Horizontal bars best for comparison.

If showing percentage, data adds up to 100 percent.

STACKED BAR CHART

Limit the number of variables for each bar.

Focus on Largest Chunk

STACKED BAR CHART

Source: Edsource

Equals 100 percent?

STACKED BAR CHART

Source: Flowing Data

STACKED BAR CHART

Simple Tools

Google Charts

DataVisual (Column only)

DataWrapper

Correlation!

Shows distribution of data.

Add trendline to test distance from average.

Great for exploring relationship between two datasets.

SCATTER PLOT

SCATTER PLOT

Tips and Considerations

Strategically label when data points are numerous.

Keep an eye out for outliers and clusters.

Correlation != Causation.

SCATTER PLOT

Thoughts?

Source: New York Times

SCATTER PLOT

Using the Trendline

Source: New York Times

SCATTER PLOT

Simple Tools

Google Charts

DataVisual

When Two Dimensions Don't Cut It

Can show up to four dimensions of data.

Uses an X-Axis, Y-Axis, Size, and Color.

Works with categorical and quantitative data.

BUBBLE CHART

BUBBLE CHART

Tips and Considerations

Think critically about what dimensions will tell the story.

Population as size may distort other points.

Only use the dimensions you need.

BUBBLE CHART

Good Use of Population as Size

Source: Flowing Data

MOTION CHART

The Most Insane Thing Ever

Source: TED

BUBBLE CHART

Simple Tools

Google Charts

REMEMBER...

Simplify.

Let the data tell the story.

Tell one story in a chart, even if there are many.

Get inspiration.