Gazetteers are secondary sources of geographical data, as they are compilations of information from various primary sources.

Cluster analysis is a statistical method that groups together observations based on their similarity in terms of multiple variables.

Data mining is the process of extracting hidden patterns and relationships from large amounts of data.

ArcGIS is a proprietary software developed by Esri, and it is widely used for analyzing and visualizing geographical data.

Cartography is the art and science of creating maps and other visual representations of geographical data.

Metadata is information about data, such as its source, accuracy, and format. It is not a type of spatial data.

Remote sensing is the process of collecting geographical data using sensors mounted on aircraft or satellites.

LiDAR data is collected using a laser scanner, which measures the distance between the sensor and the ground. It is not a type of remote sensing data.

A digital elevation model (DEM) is a three-dimensional model of a landscape that is created using LiDAR data.

Classification is a process of assigning features to different categories based on their characteristics. It is not a type of spatial analysis.

Interpolation is the process of predicting the value of a variable at a particular location based on the values of that variable at neighboring locations.

Radial basis functions (RBF) are a type of machine learning algorithm, and they are not commonly used for interpolation.

Factor analysis is a statistical method that identifies the most important factors that influence a particular phenomenon.

Confirmatory factor analysis is a type of structural equation modeling, and it is not commonly used for factor analysis.

Discriminant analysis is a statistical method that classifies observations into two or more groups based on their similarity in terms of multiple variables.