Smart Mapping Part 4: Pairing Data with Maps

There are many kinds of thematic maps and each is highly flexible in its design. This variety is a blessing because we can tell a seemingly endless number of geographic stories. It is also a curse because thematic cartography is so open-ended and dozens of decisions may have no single, obvious answer: should I use color ramps or proportional sizes? If size, which shape? How much generalization to apply? What about data classification?  Smart Mapping is designed to change all of that.

We infuse cartographic expertise directly into the ArcGIS workflow. For example, in ArcGIS Online if you choose ‘Change Style’ from your layer menu options you will see a list of drawing styles smart mapping considers suitable for the chosen attribute. Importantly, this list updates as the data you select changes – it is a live list that pairs data to the appropriate kinds of maps for those data. We all work faster when illogical or weak choices are eliminated.

There are also important differences based on the geometry type of your layer.  What Smart Mapping chooses is based on the following rules:

• Just Locations: If no attribute is selected (location only) you have the choice of the ‘Location (Single symbol)’ drawing style and in case of point layers also the ‘Heat Map’ drawing style. It will default to the Location drawing style.

• Numeric Data: If the attribute contains number values you have the choice of ‘Counts and Amounts (Size)’, ‘Counts and Amounts (Color)’, in case of point layers ‘Heat Map’, ‘Location (Single symbol)’, and ‘Types (Unique symbols)’. If your layer contains polygons and your attribute contains decimal values it will default to the Color drawing style, otherwise it will default to the Size drawing style.
• Categorical Data: If the attribute contains string values you have the choice of ‘Types (Unique symbols)’, in case of point layers ‘Heat Map’, and ‘Location (Single symbol)’. It will default to the Types drawing style.
• Dates: If your layer is based on a feature collection and you choose an attribute containing dates you have the choice of ‘Location (Single symbol)’, ‘Types (Unique symbols)’, and in case of point layers ‘Heat Map’. It will default to the Location drawing style.

• Though, independent of the type of attribute, if your layer has value domains setup on the attribute you chose it will default to the Type drawing style.

By offering the most popular choices and eliminating cartographically unwise options, we have streamlined the authoring workflow. You can click the SELECT button at any time to change it. Smart mapping will calculate suitable settings for your new drawing style. We want to encourage you to try new mapping ideas, to feel confident moving beyond the defaults of the software, and to create beautiful maps.

Co-written with Adelheid Freitag, ArcGIS Online development team