Flat, sequential list

All the grouping we've looked at so far is hierarchical, with higher-level and lower-level categories.

Another form of grouping is sequential, which is where the order of the items is important.

One way we can create order is through ranking.

For example, how are these items ranked:

The four highest peaks in the Himalayas:

1. Mount Everest—29,029 ft (8,848 m)

2. K2—28,251 ft (8,611 m)

3. Kangchenjunga—28,169 ft (8,586 m)

4. Lhotse—27,940 ft (8,516 m)

Ask Me Everything(2010)

The peaks are ordered by their height.

Notice the list is ordered and numbered (1, 2, 3, 4). Note that not all ordered lists are numbered, and not all numbered lists are ordered! (Sometimes numbered items are interchangeable.)

Also, this ranking is based on an objective measure that all the items share (height).

However, ranking can be subjective, such as by personal preference:

The Best Movie Characters Of All Time

1. Forrest Gump

2. Woody

3. Captain Miller

4. The Tramp

5. Pumbaa

Ranker.com

This list is numbered and ordered, but the order is determined by personal preference.

Another way we can order a list is by sequence. For example, steps in a recipe:

Cooking instructions

1. In food processor combine: chocolate, unsalted butter, sugar, cocoa powder, baking powder, all-purpose wheat flour, eggs, and finely grated ginger.

2. Blend until smooth.

3. Transfer the mixture into a square or rectangular pan, lined with baking paper, approximately 25x25 or 30x20 cm. Straighten with a silicone spatula or a spoon.

4. Sprinkle dried cherries and nuts on top and press into the dough.

5. Bake for 15 minutes at 180 C / 360 F.

Writelike

This type of sequential list is called a procedure.

A different type of sequential list is a timeline. For example, this is a timeline of probable events in the far future:

Probable events in the far future:

15,000 years: According to the Sahara pump theory, the precession of Earth's poles will move the North African Monsoon far enough north to change the Sahara's climate back into a tropical one such as it had 5,000–10,000 years ago.

17,000 years: Best-guess recurrence rate for a "civilization-threatening" supervolcanic eruption large enough to spew 1,000 gigatonnes of pyroclastic material.

50,000 years: Niagara Falls erodes away the remaining 32 km to Lake Erie and ceases to exist.

1 million years: Desdemona and Cressida, moons of Uranus, will likely have collided.

10 million years: The widening East African Rift valley is flooded by the Red Sea, causing a new ocean basin to divide the continent of Africa and the African Plate into the newly formed Nubian Plate and the Somali Plate.

Timeline of the far future

So you can see that ordered lists can be arranged either by rank or by sequence.

Each of these options suggests a different relationship between the items.

Write an ordered list with 4+ items. It could be ranked (by objective or subjective measures) or sequenced (as a procedure or timeline).

We've covered a lot of list basics, so let's do a quick recap before moving on.

Lists & hierarchies

Flat, sequential list