GISP Section 1 Questions with Verified Correct
Answers
Discrete Data (Quantitative)
only occurs at specific locations and has well-defined boundaries. Ex: building, roads, vector
data (AKA discontinuous or categorical data)
Continuous Data (Quantitative)
each location is a measure of something. In raster format. Ex: elevation, temperature. Can
contain fuzzy uncertain data.
Pseudo node
node at the end of a line feature that connects to only one node along another line feature.
Makes it appear as though two separate line features are one, can indicate where two line
features can be merged.
Dangle node
a point at the end of a line with no connections
Edge
line that forms a boundary between two features
Curve
a line calculated mathematically, rather than from connected vertices. AKA Parametric or
Bezier
Centroid
, the center location of a polygon. Will not always be in the polygon when the polygon is
irregularly shaped.
Area
amount of space a polygon contains
Perimeter
total measure of the length of the outside of the polygon
Raster
representation of the world as a surface divided into a regular grid of cells. Good for data that
varies continuously.
Raster Advantages
easy to understand; good for continuous, heavily variable surfaces; easy to put in and get out
of computer programs; easy for programmers to work with; easier to interpolate data, and
math can be easily performed on data; good for scanned and remotely sensed data; easy to
display and print; easier to train.
Raster Disadvantages
larger file size; non-efficient compression techniques; poor at representing points, lines,
polygons, and curves; limited in data capacity since each cell can only hold one feature or
attribute info.
Vector Advantages
more efficient for storage; small file size; accuracy is limited by the measurement process;
supports topology and can record relationships between layers/files; generalizations are
possible; can represent curves.
Answers
Discrete Data (Quantitative)
only occurs at specific locations and has well-defined boundaries. Ex: building, roads, vector
data (AKA discontinuous or categorical data)
Continuous Data (Quantitative)
each location is a measure of something. In raster format. Ex: elevation, temperature. Can
contain fuzzy uncertain data.
Pseudo node
node at the end of a line feature that connects to only one node along another line feature.
Makes it appear as though two separate line features are one, can indicate where two line
features can be merged.
Dangle node
a point at the end of a line with no connections
Edge
line that forms a boundary between two features
Curve
a line calculated mathematically, rather than from connected vertices. AKA Parametric or
Bezier
Centroid
, the center location of a polygon. Will not always be in the polygon when the polygon is
irregularly shaped.
Area
amount of space a polygon contains
Perimeter
total measure of the length of the outside of the polygon
Raster
representation of the world as a surface divided into a regular grid of cells. Good for data that
varies continuously.
Raster Advantages
easy to understand; good for continuous, heavily variable surfaces; easy to put in and get out
of computer programs; easy for programmers to work with; easier to interpolate data, and
math can be easily performed on data; good for scanned and remotely sensed data; easy to
display and print; easier to train.
Raster Disadvantages
larger file size; non-efficient compression techniques; poor at representing points, lines,
polygons, and curves; limited in data capacity since each cell can only hold one feature or
attribute info.
Vector Advantages
more efficient for storage; small file size; accuracy is limited by the measurement process;
supports topology and can record relationships between layers/files; generalizations are
possible; can represent curves.
