Summary of "Polyhierarchy in Information Architecture"

Summary of Main Ideas

Categorization of Instruments: The video discusses the complexity of categorizing musical instruments, using the piano as a primary example. The piano can be classified in multiple ways:
- As a percussion instrument (due to the hammer striking the strings).
- As a string instrument (because it produces sound through vibrating strings).
- Based on the interface used by the player (pressing keys).
polyhierarchy Concept: The speaker introduces the concept of polyhierarchy, which refers to the practice of categorizing an item into multiple categories. This approach can be beneficial for navigation and categorization in digital products, as it supports different user mental models.
Cautions of polyhierarchy: While polyhierarchy can enhance user experience by aligning with various expectations, it can also lead to confusion if overused. The speaker emphasizes the importance of:
- Not categorizing everything into every possible category.
- Using data-driven evidence to determine where users expect to find items.

When Considering Polyhierarchical Classification:
- Bias Towards Single Categories: Aim to categorize items into a single category unless there is clear evidence that users expect to find them in multiple categories.
- Use Evidence for Exceptions: Only make exceptions based on user research, such as:
  - card sorting studies: Understand how users group items.
  - Tree Testing: Evaluate the effectiveness of the categorization structure.
  - Usability Testing: Gather insights on user expectations and behaviors.
Practical Application Example:
- In a music store, categorize pianos primarily in the keyboard department.
- Only add pianos to the drum department or string instrument department if data shows that customers actively seek pianos in those areas.