Data Visualization of Hierarchical Data

Hierarchical Trees

• A root node in a hierarchical tree can have multiple children nodes.

Tree Structure

• The depth of a hierarchical tree is equal to the maximum number of children a node can have.

Binary Trees

• In a binary tree, each node can have up to two children nodes (not three).

Leaf Nodes

• A leaf node in a hierarchical tree is a node that does not have any children (not ancestors).

Visualization

• Node-Link Diagram is a visualization approach where nodes are connected by links (not contained within other nodes).

Trees in Data Structures

• A tree is a data structure used to represent hierarchical relationships.

Basic Building Blocks

• The basic building block of a tree data structure is called a node (not a leaf).

Data Modeling

• Information objects are examples of entities or objects of interest in a data model (not subjects of interest).
• The suitability of a visualization technique strongly depends on the number of dimensions in the data.
• Hierarchical relationships can be represented in a data model using trees and hierarchies.