L2.11: Assignment


Questions About Geographic Entities

GEOINT addresses questions that technology alone is not particularly good at answering. These are explanatory questions that help you make sense of what you see. Examples are:

  • Why entities are located where they are.
  • Why they have the attributes they do.
  • Why they have changed as they have.

In addition, GEOINT is often concerned with predictive questions such as what will happen at this location if this happens at that location? In general, GEOINT data and software packages cannot be expected to provide clear-cut answers to explanatory and predictive questions right out of the box. Typically, analysts must turn to specialized statistical packages and simulation routines. Information produced by these analytical tools may then be re-introduced into the GEOINT database. It is always important to keep in mind that decision support tools are not substitutes for human experience and judgment.

Most of us are interested in data only to the extent that they can be used to help understand the world around us and to make better decisions. Analytic processes vary a lot from one organization to another. In general, however, the first steps in making an analysis are to articulate the questions that need to be answered and to gather and organize the data needed to answer the questions. To follow are examples of the kinds of questions GEOINT asks about how space is organized.

Questions concerning individual geographic 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?
  • When were the entity's location, extent, or attributes measured?
  • Has the entity's location, extent, or attributes changed over time?
  • Questions about time

Questions concerning multiple geographic entities. Such questions include:

  • Questions about spatial relationships
    • 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?
  • Have the entities' locations, extents, or attributes changed over time?
  • Questions about temporal relationships

The ability to identify and make sense of the patterns we see are critical skills in GEOINT. Maps are a fundamental source of information about spatial patterns. I will teach you a beginning approach to pattern sensemaking. After a while, the approach becomes natural. I caution you not to treat this as a recipe to be followed in a rote-learning fashion. It is a guide to start you on the sensemaking process. There are two general steps in the process:

Step 1: Referring to the above questions, describe what you see to answer "what is the pattern and where is the pattern?" This is done by describing the major parts or components to the pattern as:

  • Are there contiguous clusters of roughly similar values for places in an extended geographic area?
  • What are the trends? This is, do the patterns extend in a general direction?
  • Are there discontinuities? This is, abrupt and significant spatial changes in map values for places separated by relatively short distances.
  • Are there exceptions? This is, are there isolated places that stand out from either the surrounding regional grouping or the spatial trend?

Step 2: Explanation of the pattern to answer how and why the pattern occurred. Explain the pattern by:

  • listing all of the factors, which can have an effect on the value of the phenomenon being mapped at a particular location.
  • Include in the list what effects these factors have. Is the factor likely to increase or decrease the value of the phenomenon?

Apply the factors in order to explain the components of the pattern that you described in the first step. Remember that:

  • You are trying to explain why the groupings, spatial trends, discontinuities, and exceptions exist where they do.
  • You must explain why the exceptions exist.

Before we try to make sense of a pattern, let's practice.

Practice Question A:
Examine the map of earthquakes in Figure 2.12. (You can click on the map to open the ArcGIS Online earthquake webmap.) The earthquakes are obviously geological. But, why does this pattern occur? You can find an answer here.

ArcGIS Online map of earthquakes around the world.
Figure 2.12: Earthquakes.

Practice Question B:
What causes the global pattern of malaria cases in Figure 2.13? (You can click on the map to open the ArcGIS Online malaria webmap.) Click here for an answer to Question B. Coursera link.

ArcGIS Online map of the distribution of malaria around the world.
Figure 2.13: Malaria cases.