Subcategories

So far our lists have had 2 levels: categories and items. What if we insert an extra level of subcategories?

Below are items around me right now:

Level 1: Grouped by how I feel about them
- Level 2: Then grouped by whether or not I own them.
  - Level 3: Finally the items themselves.

Things in front of me right now:

That I like:

- That I own:

--- Copy of Animal, Vegetable, Mineral

--- Case full of cables and hard drives

--- Cup of coloured pens

--- Small fabric owl from Kyoto

--- Index cards covered in notes

--- Laptop

--- Headphones

--- Set of cards from the game Dialect

--- Bag of oats

- That I don't own:

--- Screen

--- Tree

That I don't like:

- That I own:

--- Orange that looks too dry to be appetising

- That I don't own:

--- Ugly mural on the building across the street

That I'm neutral about:

- That I own:

--- Completed tax form

--- Unused keep cup

- That I don't own:

--- Daniele's Patagonia cap

--- Scissors

Writelike

Make your own list with categories and subcategories. You can use the ones we've used or make up your own.

Remember: all these groupings are about showing relationships between items. So when you look at your list, think about whether there are any interesting or revealing relationships you could highlight by grouping items in a particular way.

Nope! You can create different subcategories in different groups if you wanted. Feel free to experiment!

Make your own 3-level list with categories and subcategories.

How did you go? Again, the most interesting thing here is to compare your list with someone else's and see how they see the world compared to you.

We could keep going, adding more levels to the list, but we won't—you get the idea! Let's move on.

Have you noticed how, in all the lists we've seen so far, you could change the order of items without affecting the list? (Though you can't move items between categories.)

Even if we are using multi-level hierarchies, these are called unordered lists.

A different way to relate items is through sequential relationships, with an ordered list.

Lists & hierarchies