What is the AEIOU method, and what does each letter prompt you to observe?

Question

Accepted Answer

A context-analysis checklist for understanding a situation by observation — Activities, Environment, Interaction, Objects, Users — so you grasp the real problem before designing for it.
AEIOU is a framework for structured observation, typically used when studying how people actually behave in a setting (rather than how you assume they do). Each letter is a lens:

Letter
Lens
Asks

A
Activities
What are people doing? What are their tasks? What happens before and after?

E
Environment
What does their surroundings look like — the rooms, the noise, what else is going on?

I
Interaction
How do people interact with the system, and systems with each other? Where are the interfaces?

O
Objects
What objects and devices are used, by whom, and in what setting?

U
Users
Who are the different users, what are their traits and roles, and what influences them?

It forces a complete, structured sweep of a usage context so you don't fixate on one aspect (say, the software) and miss that the real issue is the noisy room or the user's actual task.

Letter	Lens	Asks
A	Activities	What are people doing? What are their tasks? What happens before and after?
E	Environment	What does their surroundings look like — the rooms, the noise, what else is going on?
I	Interaction	How do people interact with the system, and systems with each other? Where are the interfaces?
O	Objects	What objects and devices are used, by whom, and in what setting?
U	Users	Who are the different users, what are their traits and roles, and what influences them?