Icecream 05

Causation vs. Correlation

 

Use the following website to Answer questions 1-5. When you have answered these question write a 5-6 sentence paragraph explaining what you have leaned

http://weblogs.baltimoresun.com/news/crime/blog/2011/01/open_baltimore_crime_by_month.html

What month has the highest amount of Burglaries?

what about Larceny?

Auto theft?

Aggravated Assault?

Robbery ?

 

 What makes a good graph?

Check the data

This should be obvious. Data forms the foundation of charts and graphs. If your data is weak, your graph is weak, so make sure it makes sense. Start with some simple graphs to see if there are any outliers or weird spikes. Verify anything that doesn’t make sense. You might be surprised how many data entry typos you find in the spreadsheets people send you.

Explain encodings

Maybe you use a color scale to indicate magnitude or the size of a square to represent values. Maybe it’s a combination of both. Explain what these encodings are supposed to indicate, and don’t assume the reader knows what everything means. Most likely he doesn’t.

You can provide explanations in a variety of ways, but the most common are providing a legend, directly labeling shapes, or describing your graphic in a lead-in paragraph.

Without your pointers, it’s a guessing game for the reader.

Label axes

Oh look, what fine gridlines you have there. Without labels or any explanation, they’re just decoration. Label your axes so that readers know what scale points are plotted on. Is it logarithmic, incremental, exponential, or per 100 flushing toilets? Without axis labels, I always assume it’s that last one. Also, in most cases, you’ll want your value axis to start at zero.

Include units

Include some units while you’re at it. If you just leave it with naked numbers, it could mean anything from a percentage, to a volume, to the number of chickens that crossed the road. Again, you want to eliminate the need for any guesswork from the reader.

Keep your geometry in check

If your geometry is wrong, this will be the first thing people call you on, especially if you use bubble size to indicate a numeric value, so you better get it right. You’ll also probably have the pleasure of seeing your work highlighted negatively on some nerdy blog.

Here’s how it works. Size circles and other two-dimensional shapes by area, unless it’s a bar graph or something like that. When you size circles by diameter, you end up with circles that are way out of proportion, and that’s a bad thing.

Include your sources

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