GISP - Geographic Information Systems Professional Cartography and Visualization Questions and Answers — Questions and Answers
Question 1: A cartographer is creating a thematic map showing population density by county for the entire United States. To ensure that each class in the legend represents an equal number of counties, which data classification method is most appropriate?
- Equal Interval
- Natural Breaks (Jenks)
- Quantile (Correct answer)
- Standard Deviation
Correct answer: Quantile
The Quantile classification method places an equal number of data values into each class. This is ideal for the scenario described, as the goal is to have the same number of counties in every category, which can highlight the relative position of data values.
Question 2: When designing a map for a presentation, a GIS professional wants to ensure that the most important information, such as the main thematic layer, immediately draws the viewer's attention. Which cartographic principle is most directly concerned with this goal?
- Map Projection
- Visual Hierarchy (Correct answer)
- Cartographic Generalization
- Scale
Correct answer: Visual Hierarchy
Visual hierarchy is the arrangement of map elements to emphasize the most important information. By using visual variables like size, color, and position, cartographers can guide the viewer's eye to the most critical parts of the map first, such as the primary thematic data.
Question 3: A GIS analyst is tasked with creating a series of maps from a highly detailed national road network dataset for use at various scales, from a national overview down to a local street view. The process of simplifying the linework and reducing the number of features for the smaller-scale maps is known as:
- Buffering
- Reclassification
- Geocoding
- Cartographic Generalization (Correct answer)
Correct answer: Cartographic Generalization
Cartographic generalization is the process of reducing the complexity of geographic features so they can be represented clearly at smaller scales. This includes techniques like simplification (reducing vertices in a line), aggregation (grouping features), and selection (choosing which features to display).
Question 4: Which of the following map projections would be most suitable for a navigational chart of the world's oceans, where preserving the shape of coastlines and maintaining true direction for rhumb lines is the highest priority?
- Albers Equal Area Conic
- Mercator (Correct answer)
- Azimuthal Equidistant
- Winkel Tripel
Correct answer: Mercator
The Mercator projection is a conformal projection that preserves angles and shapes locally. A key feature is that rhumb lines (lines of constant bearing) are represented as straight lines, which is invaluable for navigation. However, it significantly distorts the size of areas near the poles.
Question 5: A choropleth map is being created to show the percentage of the population with a college degree in each state. Which of the following is a critical consideration to ensure the map is not misleading?
- Using raw population counts instead of percentages
- Using a unique color for each state
- Normalizing the data (Correct answer)
- Using a very large number of classes (e.g., >20)
Correct answer: Normalizing the data
Normalization is crucial for choropleth maps to account for the different sizes of enumeration areas (like states). By converting raw counts (e.g., number of college graduates) into a rate or percentage (e.g., percent of the total population), the map accurately portrays the variable's concentration and avoids misleading representations where larger areas appear more significant simply due to their size.
Question 6: In cartographic design, what is the primary purpose of a map's legend?
- To indicate the map's scale and projection
- To orient the map reader with a north arrow
- To provide the source and date of the data
- To explain the meaning of the symbols and colors used on the map (Correct answer)
Correct answer: To explain the meaning of the symbols and colors used on the map
The primary function of a legend is to interpret the map's symbology. It serves as a key that links the visual elements (symbols, colors, line styles) on the map to the real-world features or data values they represent, allowing the reader to understand the map's content.
GISP - Geographic Information Systems Professional Cartography and Visualization Questions and Answers
A cartographer is creating a thematic map showing population density by county for the entire United States.
To ensure that each class in the legend represents an equal number of counties, which data classification method is most appropriate?