<p>Measure: Depth of Inheritance Tree</p><p>A.Definition Node: A class in the inheritance tree Root Node: A node with no parents. Leaf Node: A node with no children. Edge: An edge connects one node to another. In an OO context, it denotes the inheritance of the super class by the subclass. Path: The traversal from one node to another node. Depth: The longest path (the greatest number of edges) from the root node to a leaf node.</p><p>B.Entities, Attributes and Their Relationships A1. Entity The entity is the inheritance tree.</p><p>A2. Attributes An attribute of the inheritance tree is its depth.</p><p>A3. The relationship An inheritance tree must have a root node. This implies that an inheritance tree must have at least one node. Thus, every inheritance tree has a depth (See definition).</p><p>C.Units and Scale Types and Their Relationships B1. Units The unit is the edge between two nodes. Note: Another unit could be a node, if the definition of depth was changed to greatest number of nodes from the root node to a leaf node, including both the root and leaf node.</p><p>B2. Scale Types The scale type is a ratio scale because there is an absolute zero and the ratios between two or more inheritance trees are preserved.</p><p>B3. The Relationship An edge is a ratio scale unit of depth. </p><p>D. Values The value is the count of edges in the longest path from the root node to a leaf node. The value applies to the inheritance tree. It measures the depth of the inheritance tree and the unit is in number of edges.</p><p>E. Properties of Values The permissible values are non-negative integers. The set of permissible values is infinite, unbounded and discrete.</p><p>F. Measurement Instrument The measurement instrument is counting the number of edges for the longest path from the root to a leaf node.</p>