GIS Conceptual Foundations 5 — Questions and Answers
Question 1: Which type of map projection preserves area but distorts shape?
- Conformal projection
- Equal-area projection (Correct answer)
- Equidistant projection
- Azimuthal projection
Correct answer: Equal-area projection
Equal-area (equivalent) projections maintain correct area relationships across the map but distort the shapes of features.
Question 2: What is the fundamental difference between 'discrete' and 'continuous' spatial phenomena?
- Discrete phenomena vary smoothly across space; continuous phenomena have abrupt boundaries
- Discrete phenomena have defined boundaries; continuous phenomena vary smoothly without clear boundaries (Correct answer)
- Discrete data is always stored in raster format; continuous in vector
- Continuous phenomena apply only to point data; discrete to polygon data
Correct answer: Discrete phenomena have defined boundaries; continuous phenomena vary smoothly without clear boundaries
Discrete phenomena (e.g., land parcels, roads) have distinct, definable boundaries, while continuous phenomena (e.g., temperature, elevation) vary smoothly across space.
Question 3: What is the purpose of a 'coordinate transformation' in GIS?
- To add new attributes to a feature class
- To convert features from one coordinate reference system to another (Correct answer)
- To merge two overlapping spatial datasets
- To generalize complex geometries for smaller-scale display
Correct answer: To convert features from one coordinate reference system to another
A coordinate transformation mathematically converts feature coordinates from one reference system (e.g., NAD27) to another (e.g., WGS84) so datasets align correctly.
Question 4: In the context of GIS, what is 'spatial data infrastructure' (SDI)?
- The hardware servers used to store raster datasets
- A framework of policies, standards, and technologies enabling the sharing and use of spatial data across organizations (Correct answer)
- A type of network topology used in urban planning GIS
- The file directory structure for organizing GIS project files
Correct answer: A framework of policies, standards, and technologies enabling the sharing and use of spatial data across organizations
A Spatial Data Infrastructure provides the policies, standards, technologies, and institutional arrangements needed to coordinate and share geographic information across agencies and jurisdictions.
Question 5: Which statement correctly describes the difference between 'nominal' and 'ratio' measurement scales in GIS attribute data?
- Nominal data has a true zero; ratio data is categorical with no order
- Nominal data categorizes features with no inherent order; ratio data has a true zero and meaningful proportions (Correct answer)
- Both scales support the same mathematical operations in GIS
- Ratio data is used only for geographic coordinates
Correct answer: Nominal data categorizes features with no inherent order; ratio data has a true zero and meaningful proportions
Nominal data classifies features into unordered categories (e.g., land use type), while ratio data has a true zero point allowing proportional comparisons (e.g., population count).
Question 6: What does 'data generalization' mean in GIS cartography?
- Adding more detail to a feature for large-scale maps
- Simplifying or abstracting features to match a smaller map scale (Correct answer)
- Converting raster data to vector format
- Applying a coordinate transformation to a dataset
Correct answer: Simplifying or abstracting features to match a smaller map scale
Generalization reduces the complexity of features (e.g., smoothing coastlines, merging small polygons) so they remain readable and meaningful at smaller map scales.
Question 7: Which GIS principle states that spatial data should be captured once and shared many times rather than duplicated across agencies?
- Single source of truth principle
- Layer cake principle
- Collect once, use many times principle (Correct answer)
- Spatial autocorrelation principle
Correct answer: Collect once, use many times principle
The 'collect once, use many times' principle underpins spatial data infrastructure, advocating for authoritative datasets shared across organizations to reduce redundancy and inconsistency.
GIS Conceptual Foundations 5
Which type of map projection preserves area but distorts shape?