1. Human Capabilities: Attention
CS352

2. Announcements 1. Choice for next Wednesday (Week 9).
2. Team presentations on Monday of Week 10.
3. Last 5 minutes of today’s class.

3. Attention
Selecting what to focus on, at a point in time, from the range of possibilities.
Banner ads steal attention “pre-brain”.
Attention also happens in brain.
We focus on what we think is relevant to our task.
Attention highly dependent on our limited short term memory (which is small).
HOWEVER -- if didn’t make it thru senses, not a contender. 👁

4. Brain attention Can brain multi-task? Then ...?
No. Mostly attend to one thing at once.
Then ...?
Like in operating systems: Interrupt system, context switch.
Cost of context switch.
Missed triggers.
Thus, UIs should encourage this with care.
Hands-free cells while driving? s while in talks/meetings/classes?
Flow? Depth of concentration?

5. What do people (usually) attend to?📝
The task, not the tool.
Ex1: The words you’re writing, not the pencil.
Ex2: The story in the book, not the physical book.
If have to attend to the tool, might forget ...
Ex1: Pencil gets too dull, attend to pencil (sharpen).
 Have system (last few words you wrote) show where you left off.
External cognition saves the day!
Ex2: Doorbell rings, put down book; where was I?
 Let user mark where you left off. (eg, bookmark).

6. Implications People won’t pay much attention to a UI.
Very surface-level attention.
Want to do tasks familiar way (remember Abby?)
UI should allow focus on task, not UI.
“Don’t make me think!” (about the UI)
Pay a bill
Transfer $ to savings
Pay dentist via fund transfer
Change PIN
Open new acct
Buy travelers checks
This is Fig 8.3, p. 100, Johnson book.
The list of tasks is about: which widget to you push to do these things.

7. Demanding Brain’s Attention: Interruptions
When COMPUTER decides to call attention to something.
Four important kinds:
Immediate
For when MUST pay immediate attention.
Mediated
Computer decides when to interrupt.
Scheduled
Negotiaated
Best for productivity AND learning.

8. Attention Take-aways (Basics for UIs)
Users can’t attend to everything at once.
If info does not make it thru senses,
brain can’t attend to it.
Once in brain:
users attend to what seems most relevant. (Remember Info Foraging Theory?)
User has the right to their own attention.
There is a cost to making them attend to UI.
Do not impose it arbitrarily.