Notation for total specialization — evaluate the statement: “Total specialization is represented by double lines between the supertype and subtype on an Enhanced ER (EER) diagram.” State whether this is correct or incorrect.

Introduction / Context:
In EER diagrams, participation of a supertype in its subtypes can be total (every supertype instance must be a member of at least one subtype) or partial (some supertype instances may exist with no subtype). Many notations indicate total participation using a double line between the supertype and the specialization arc or subtype connector.

Given Data / Assumptions:

• We refer to widely used ER/EER notations (e.g., Chen style and variants).
• Total vs. partial is distinct from disjoint vs. overlapping.
• Tools may vary in glyphs but commonly use a double line for total participation.

Concept / Approach:
Total specialization means no supertype instance exists without being classified under at least one subtype. The double line visually enforces this rule on the diagram. Partial specialization uses a single line, allowing unclassified supertype instances.

Step-by-Step Solution:

Verification / Alternative check:
Review CASE tool help and textbook conventions; double lines are consistently used to denote total participation, confirming the statement’s correctness in mainstream notations.

Why Other Options Are Wrong:

• “Incorrect” contradicts common notation practice.
• “Only in Crow’s Foot” is too narrow; Chen variants also use double lines.
• Disjointness is orthogonal to participation and does not affect the double-line rule.
• Tool differences exist, but the double-line convention is widely recognized.

Common Pitfalls:
Confusing total participation with disjointness; forgetting to verify business rules when choosing total vs. partial; misapplying crow’s foot symbols to specialization connectors.

Final Answer:
Correct