So far, we have learned why geographic data are unique, how information differs from data, and how various forms of geographic information can be represented in computers and communicated to human beings. Let us now consider the types of questions we can ask, now that we are equipped with this knowledge.
The simplest geographic questions pertain to individual entities
Such questions include:
Questions about space
- Where is the entity located?
- What is its extent?
Questions about attributes
- What are the attributes of the entity located there?
- Do its attributes match one or more criteria?
Questions about time
- When were the entity's location, extent, or attributes measured?
- Has the entity's location, extent, or attributes changed over time?
Simple questions like these can be answered effectively with a good printed map, of course. However, GIS becomes increasingly attractive as the number of people asking the questions and the required level of precision grows, especially if they lack access to the required paper maps.
Questions concerning multiple geographic entities
- Do the entities contain one another?
- Do they overlap?
- Are they connected?
- Are they situated within a certain distance of one another?
- What is the best route from one entity to the others?
- Where are entities with similar attributes located?
Questions about attribute relationships
- Do the entities share attributes that match one or more criteria?
- Are the attributes of one entity influenced by changes in another entity?
Questions about temporal relationships
- Have the entities' locations, extents, or attributes changed over time?
Notice that all of these questions deal with where things are, how things relate to other things, and how things change or persist relative to these locations. These are the kinds of questions that GIScience and professionals in the geospatial industry are prepared to answer.
Registered Penn State students should return now take the self-assessment quiz about Geographic Questions and Properties.
You may take practice quizzes as many times as you wish. They are not scored and do not affect your grade in any way.