Build Up Only Principle

The Build Up Only Principle restricts relationships between items to one direction (build up).

Why is this principle necessary?

Relations between items are very helpful if clear, like a good map. Linking all items together, however, causes two problems:

• It clutters the map, which violates the Usability Principle.
• It can lead to repetition, which violates the Single Source Of Truth Principle.

Example 1: Ignoring the Build Up Only Principle

• Thought A: This is Thought A. It leads to Thought B.
• Thought B: This is Thought B. It is derived from Thought A.
• In the above example, identical information is needlessly repeated.

To solve this problem, the Build Up Only Principle is a convention that directs that only children and only derivations should be (actively) linked to parents, but not the other way around.

Example 2: Following the Build Up Only Principle

• Thought A: This is Thought A.
• Thought B: This is Thought B. It is derived from Thought A.

In the above example, identical information is not needlessly repeated.

Example 2a: Following the Build Up Only Principle with derivations

• Thought A: Animals have a skin.
• Thought B: Since birds are animals, birds also have a skin.

Example 2b: Following the Build Up Only Principle with media items

• Media A: The Lord of the Rings (book)
• Media B: The scene in "Lord of the Rings (book)" where Frodo first sees the ring.

How automation can restore clarity

The problem in example 2, 2a and 2b is that, when looking at the first item, one cannot see the derivations and children, which reduces clarity (see Usability Principle). This, however, can easily be solved by automation, since the principle only applies to input in the site, not what is displayed.

Thus, the solution is to follow the principle regarding input but to still see all the interconnections on the relevant pages:

Example 3: Following the Build Up Only Principle and using automation

• Thought A: This is Thought A.
  • Automated list of derivations: 
    • Thought B.
• Thought B: This is Thought B. It is derived from Thought A.
  • Automated list of derivations: 
    • Thought C, Thought D, Thought E.