3 types of bar charts - Show and Tell Tuesday part 7
For the magical number seven in this series, I'm featuring an in-depth look at three types of bar charts using data on flooding.
The term "bar chart" typically refers to showing categorical data (like colors, countries, objects, etc.) but these visuals use the bar to show a variety of concepts.
Histogram
Histograms show frequencies within a range of numbers (like ages, time periods, percentages, etc.). (Note: Pareto charts are altered histograms with an added line graph.)
Histograms reveal patterns within the distribution of data. The examples below show how these patterns are generally described.
Skewed, in this case to the right (as opposed to symmetric when values are evenly distributed):
Unimodal, meaning there is one dominant average:
Multimodal, meaning there are multiple prominent values (bimodal would mean there are two distinct poles):
Bullet graph
A bullet graph is a simplified way to show a single measure, compare it to targets or other measures, and show it in qualitative context (poor, good, excellent, e.g.).
It is considered an alternative to traditional dashboard gauges, which too often display less information with more clutter.
The example below shows how the number of U.S. floods in 2014 (blue bar) compares to the number in 2013 (black line). (The shaded areas underneath show the 60th, 80th, and 100th percentiles of the number in 2013.)
Waterfall chart
This is a way of visualizing data to better understand how an initial value is effected by sequential positive and/or negative values.
In a waterfall chart, the initial value is a full vertical bar and ones following are floating (which is why they may also be called flying brick or Mario charts) and color coded to indicate positive or negative.
The example below shows only positive increase as the bars represent increasing amounts of land affected.
Stay tuned for the next blog about more visuals showing change over time.
In the meantime, be sure to check out other fun visuals:
If you liked learning about these visuals, please share these blogs with others who may benefit the same!