1. Cognition: Memory

2. Cognition
What goes on in our heads when we carry out activities (eg, use UIs)?
Our heads do:
attention, perception, memory, learning, speaking/reading/listening, problem-solving/reasoning
underlined is what I’ll focus on in the next few lectures

3. Memory
Number activity:
BRING NUMBER.

5. Memory (cont)
Chunking
UIs use this.

6. Memory (Cont.)
Number activity:
BRING NUMBER.

7.
Prev was:

8. Memory (cont) UI implications from these two activities?
Leverage to use chunks..

9. Structure of memory The shortest of short term memory (STM)
Demonstration.
The Working Memory part of STM.
Still volatile and small.
Not really a “Place” – more like “pointers”.
eg: in book’s warehouse analogy, it’s a small number of searchlights into LTM.
Long term memory (LTM)
Everything else.
Mostly when we say “memory”, we mean LTM.

10. Recognition and Recall: Money Activity #1
Draw a $1 bill
Compare to Recall: How well did they do at drawing one?

11. Recognition and Recall: Money Activity #1
Recognition: can they recog the right one.
Compare to Recall:

12. Recognition and Recall
GUI strength: emphasize recognition over recall.
But usually slowed down by need for visual scan in GUIs.
UI solution?
Solutions: KB shortcuts let people use either one.

13. People storing/retrieving knowledge
Declarative knowledge
NYC is north of Miami.
To get key out of ignition, car must be in “park”.
Easy to teach.
Procedural knowledge
How to spin a basketball on 1 finger.
How to boot a smart phone into recovery mode.
Best taught by demo, learned by practice.

14. T&T #8: Memory Challenge
What was the question?
Related to Invisible Element: here the choices may be in front of me – but I don’t recall the procedure.
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15. Wait, what elevator?
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16. Say what?!
The Xbox One Voice Command cheat sheet. Shared by Major Nelson on Twitter
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17. Encoding and (lack of) precision
How we encode affects:
what we retrieve (recall or recognize) and
how we retrieve
Money activity #2 (if time permits)

18. Which is the US penny?

19. Ways to encode (and constraints)
Appearance attributes, sound, rhythm, rhyme.
Traveling performers: how did they do that?
Thru encoding tied to constraints. (Storage for retrieval).
Rhythm
Rhymes with
Must make sense
Example: the Raven

20. Encoding (cont.) Retrieval So, reduce and/or facilitate encoding:
Word guessing activities
So, reduce and/or facilitate encoding:
Constraints reduce encoding needed.
Support external cognition (stay tuned) to remove need to encode.
eg: Excel’s arrows make dependencies explicit.
Provide users a variety of ways to encode (eg, color, flagging, position).
eg: forgot filename, but it’s the red folder.

21. Case study
The Microsoft Office (past) rearranging of menus due to recency.
Think about chunking/grouping
Think about imprecision of encoding.
What will I do if don’t see what I want?
Does this mean “most recent” is always a bad idea in a UI?

22. Encoding (cont.) Different amount of encoding needed for:
Remembering a bunch of arbitrary things.
Remembering things with meaningful relationships.
Hotel is on north side of town.
“Remembering” things that can be derived.
Tied to “mental models” (stay tuned).

23. Implications for your Project
Avoid burdening long-term memory:
Think about: recog/recall, practice, chunking, declarative vs. procedural, encoding, constraints
Why consistency matters: reduces LTM burden
Ideas:
Security problems due to LTM (book p )
Grocery system content
Grocery system UI devices
Discussion: Your project examples?
Passwords: this is why we use obvious passwords, and/or write them down.
Security questions: The book points out that we can’t remember which answer – which pet name did I use?
Grocery system content: brand I bought before?
Grocery system UI devices: how to get subtotal?