Annotation is a crucial component of a good dataviz. It can turn a boring graphic into an interesting and insightful

Annotation is a crucial component of a good dataviz. It can turn a boring graphic into an interesting and insightful way to convey information. Dataviz is often separated in two main types: exploratory and explanatory analysis. Annotation is used for the second type.
Our current attention span for looking at things online is, on average, less than five seconds. So if you can’t grab someone’s attention within five seconds, you’ve likely lost your viewer. Adding accurate annotation can greatly help to grab audience attention. Use keywords, shapes, colors and other visuals to help them go straight to the point.
Annotation is a general concept, and hundreds of different ways to annotate a chart exist, depending on the context.
What are effective ways to leverage annotation in data visualizations? Provide 3 examples of how you would effectively use annotation in a data visualization. Describe how you would use them to keep viewers attention.
Discussion Length (word count): At least 250 words
References: At least three peer-reviewed, scholarly journal references.