Types of map visualizations
Social Explorer supports three types of map visualizations:
- shaded area
- bubble map
- dot density
Shaded area is used to represent quantities on a map by varying colors. This type of visualization is best used when visualizing normalized values, such as percentages, medians, or averages. Values are grouped into classes, and each class is represented by a particular color.
There are two major types of shaded maps: sequential and diverging. Sequential shading uses a gradient of one color. This is useful when you're trying to visualize ranked data, such as population density. The lighter shades of the gradient might represent lower population density, while the darkest shades of the gradient will conversely represent the highest population density. One side of the spectrum will be darker and the other one lighter. Diverging and converging color palettes have two contrasting colors on each end of the spectrum and are used when the data values trend inward and outward respectively. For example, you want to visualize the change in housing prices using the diverging scheme. You might use green shades for lower change in housing prices, red shades for higher change in housing prices, and white for no change. This spectrum will be the darkest at the ends, and the lightest in the middle.
Bubble maps are used to represent quantity using symbol sizes. For example, you might use larger circles to represent areas with a larger population. Just like with the shaded area, values are grouped into classes, and each class is represented by a particular bubble size. Unlike shaded area, all circles are usually the same color.
When using proportional symbols, on the other hand, values are not grouped; the size of the proportional symbol reflects the actual data value. The challenge, of course, arises when you have too many values and the difference between symbols may become indistinguishable, or symbols for high values might become so large that they obscure other symbols.
Social Explorer supports shaded bubble maps for certain variables. For example, when visualizing Total Population: White Alone, the size of the bubble will indicate the number of the white population and all the bubbles will be the same color. However, if you enable percentages in the options, the values will be calculated into percentages and each group of percentages will be represented by a different shade of the color. While you can tweak the span of each group, groups are divided into increments of 5%.
You can use dot density to represent an amount within an area. Each dot represents a specified number of variable items. It's worth noting that the placement of dots within an area is random and doesn't represent actual locations. Instead, pay attention to how close the dots are. The closer the dots, the higher the variable density in that area.