Communicating with data visualization

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# Communicating with data visualization
### Camille Seaberry, DataHaven
### March 15, 2018

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# Goal of this workshop

.font130[Data visualization is way too big a field to cover in one morning! But these are some starting places for improving your use of data visualization.

I'm not a data viz genius, so probably any of the charts I've made here could be improved upon.]

.font150[Follow along: https://camille-s.github.io/viz]

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# What is data visualization?

.font110[
> *The representation and presentation of data to facilitate understanding*

-- Andy Kirk, "Data Visualisation: A Handbook for Data Driven Design"

> *Data graphics visually display measured quantities by means of the combined use of points, lines, a coordinate system, numbers, symbols, words, shading, and color*

-- Edward Tufte, godfather of data visualization, "The Visual Display of Quantitative Information"
]

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# Maybe you don't need a visualization

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<img src="index_files/figure-html/unnamed-chunk-11-1.png" width="576" />

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Chart serves *some* purpose, but you might be better off with just text:

* Working men's median income is $51,367, compared to women's median income of $35,681
* On average, working men out-earn working women by $15,686 each year
* On average, women earn 69 cents on the male dollar

]

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# Maybe you don't need a visualization

.pull-left[
* A few overview stats---especially if comparisons wouldn't be appropriate

![from https://ct-data-haven.github.io/nhv2016/](nhv_profile_table.png)
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.pull-right[
* Bullet points

![from Community Progress Report 2016](cwi_bullets.png)
]

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# Questions to ask yourself

.font120[
If you *do* need a visualization, be intentional about what you create

What's your purpose?

* Comparing two or more observations
* Comparing values changing over time
* Showing parts of a whole
* Finding relationships between values
* Placing numbers on a map
* Distributions of values
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# Purpose

## Comparing observations

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# Purpose

## Parts of a whole

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# Questions to ask yourself

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* Who's your audience?
  + Make charts for yourself to understand your data as well
* What's the purpose?
* What do you need to communicate? What's the takeaway?
* What can you do without?
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# Focusing on your audience

Example: boxplots

Statisticians: 😍. General audience: 🤔

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# Focusing on your audience

General audiences often more concerned with averages or summary figures, not distributions.

Or pair a simple chart with more detailed text like "Low-income rates vary greatly throughout Greater New Haven's census tracts, with rates in some tracts in the single digits, while many city tracts have rates over 50%."

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# What's the purpose?

Hard to read, and unclear what the purpose is

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# What's the purpose?

Purpose: show differences in income between towns

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# What's the purpose?

Purpose: to show income by gender in each town

Alternatively, could order by largest pay gap

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# Basic guidelines

.font150[
* Figure out what you're trying to show, and why
* Use an appropriate chart/visualization type
* Map ink to values
* Get rid of junk and distractions
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# Basic guidelines

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# Basic guidelines

.font150[Previous guide: Curtis Newbold, [The Visual Communication Guy](http://thevisualcommunicationguy.com/2017/06/05/which-chart-should-i-use/)

More detailed guide to picking charts: http://annkemery.com/wp-content/uploads/2017/10/AnnKEmery-FSI-Visualization-Handout.pdf]

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# Bad habits

.font120[
* Muddying your data
* Telling inaccurate stories
* Visual cues that are flashy but contribute nothing/interfere with understanding (see any cable news channel)
* Unexamined use of pie chart, 3D, shadows, etc
* Encoding information that isn't actually there---e.g. do you actually need all those colors?
* Comparing things that are not actually comparable
]

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# Bad habits

## Data mud

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# Bad habits

## Fox News-ing your data

![fox news](Fox-News-bar-chart-1.jpeg)

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# Bad habits

## 3D

If you aren't solving differential equations or plotting terrain, you probably don't need 3 dimensions.

Where should you be reading values?

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# Bad habits

## Pie charts

Google "pie charts are evil." There's almost always a better way.

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# Bad habits

## Pie charts

Stacked bars are easier to compare between observations

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# Bad habits

## Visualizing information that isn't actually there

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