Data Visualization How to

8/20/2019 Data Visualization How to

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Data Visualization

A primer on best practices

Lazaro Gamio | @LazaroGamio

https://twitter.com/lazarogamiohttps://twitter.com/lazarogamio


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What we’re going to go over

1. Evaluating data2. Finding stories in your data3. Finding a shape for your story


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Where I’m coming from, and the type o

we do at @PostGraphics.

Some context


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http://www.washingtonpost.com/graphics/world/world-happiness-2015/


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http://www.washingtonpost.com/graphics/world/world-happiness-2015/http://www.washingtonpost.com/graphics/world/scaling-everest/


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http://www.washingtonpost.com/graphics/world/scaling-everest/http://www.washingtonpost.com/wp-srv/special/national/cia-interrogation-report/word-count/


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http://www.washingtonpost.com/wp-srv/special/national/cia-interrogation-report/word-count/


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http://www.washingtonpost.com/graphics/health/how-fast-does-measles-spread/


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Feel free to interrupt


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Data needs to be found and vetted

the same way sources are.

Evaluating data


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It doesn’t make the process any easi

There’s so much of it


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That’s also just one of many places wh

data lives. Here’s a random exampl

Gasp.


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And neither will my audience.

I have no idea what this


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384,499 rows of goodness.It was a 63 mb spreadsh


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There’s just more to edit and sift thro

Lots of data ≠ Easy dat


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Take it out to dinner and a movie.Ask about its hopes, dreams and aspira

You need to spend timwith your data.


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Data is more than the final product.1. Who collected the data?2. Who inputted the data?3. Who formatted the data?

4. How is the data being delivered?5. Who’s giving it to you?6. Is your data recent?

Who is your source?


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Population of Azerbaij

CIA WorldFactbook

Wikipedia


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World Bank

Population Referenc


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1. Data is often very specific.2. Data is really big.3. Your editing process begins at selecti

dataset.

4. You need to put in a lot of work to prodata into something digestible.

Takeaways


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What do you want to learn? Most

importantly, what do you want your reto learn?

What does your data sa


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Questions to ask

1. Who’s the ‘mostest?’2. Who’s the ‘leastest?’3. What is the ‘middle?’4. Who are the outliers? Why?

5. Is there a trend over time?6. Does this trend correlate with anothe

trend?


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1. It may be a good story.

2. Your data may be flawed.3. It may mean nothing.

Investigate outliers


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Sometimes large values distort your m

and can skew your perspective of the dDon’t add to the confusion!

Mean vs. Median


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Mean: $513,000Median: $350,000


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Do you know why there

is a variation? You should.

Trends


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Correlation ≠ Causatio


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1. Ask answerable questions of your dat2. Learn the limitations of your dataset3. Once you have findings, double-chec4. Then, Triple-check.

Takeaways


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Before you start

1. Do you really need a chart?2. Are you charting discrete quantities?3. Are you charting a time series?4. What do you want to draw attention

5. Is your data geographical?6. If so, does location make a difference


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The most important thing is knowing exwhat you want to tell. The previous two

are the most important.

Content is king


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Are you trying to show one important v

with a couple of other values for cont

Charting the mostest


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The Mostest.


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Do you have data that changes over ti

Chronological data


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A simple trend


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While maps are often useful, they are o

not the best tool for your story.

Resist the urge to map


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Gun de

People married tosomeone they metin high school

http://www.slate.com/articles/news_and_politics/crime/2012/12/gun_death_tally_every_american_gun_death_since_newtown_sandy_hook_shooting.html


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Do it for the children.

Don’t make

population maps


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Have two datasets that make sense tog

and help tell the same story?

Two Charts


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Two trends.

T k


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1. Keep it simple. Your readers willappreciate it.

2. Pick the chart that best proves your p3. Tell the reader what they should be lo

at.4. If appropriate, tell the story in multip

charts.

Takeaways


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Excel, Google Docs, Tableau, Datawrap

Matplotlib, D3, Adobe Illustrator, et

Tools


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Google Docs/Excel


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Great options


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D3.js


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Questions?


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Lazaro Gamio | @LazaroGamio

Thanks!
https://twitter.com/lazarogamio

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Data Visualization How to