The topic of mental maps is extensive and thus will appear over the span of three entries.
Understanding the Basic Concepts
A mental map is a way of organizing and understanding information. For example, I could give you a list of 12 items: sky, tree, flower, building, seed, car, cat, pen, newspaper, dumpster, paint can, and squirrel. My list is not very meaningful by itself, but you might start arranging the objects to give them meaning. Maybe you would divide them into living and dead objects, then plant and animal. You may create a category for objects used to mark other objects for the pen and paint can. Or maybe you would start to create a picture with the objects in it where you see them belonging. Your picture will likely include objects not on the list, such as a road, a bridge, and a sidewalk, but you already have a location for them in case I add them to the list. Your mental map helps you find meaning and purpose along with navigating and understanding information. Humans automatically search for meaning in order to be able to manage an otherwise overwhelming onslaught of stimuli.
For digital content, a mental map is how a user organizes the different types of digital information or tasks found in websites, applications, PDF’s, and more. People naturally create mental maps because it is easier to remember and navigate content if they interact with and organize it into a framework that makes sense to them.
For example, someone is more likely to be able to go back and find or recall important characteristics of a flower if the flowers on a website are organized according to qualities such as petal structure, area where they are found, or proper occasions to put them in an arrangement. On the other hand, if someone is accessing flower content presented without any clear structure, they probably will retain less information or have to go through the content multiple times in order to start creating categories and relationships between the flowers.
Screen reader and magnifier users also create mental maps, and in some ways depend more heavily on them to facilitate every part of accessing digital content. If you were trying to get to the bathroom in the middle of the night without turning on any lights, it would be easier to do if you knew the layout of the area between your bed and bathroom from memory, instead of trying to find it anew every time. In the same way, users with low and no vision can expedite their use of digital content by knowing the location of the parts they care about. Although users are likely to start creating a map as soon as they interact with your content, you can help the process by organizing content in a way that suggests order and relationship.