Woche 8 - Visual Interface Design & Interaction I

Question 1

a) what is a mental model?
b) what ist the mission of designers related to mental models?

Answer 1

a) what the user believes about the system at hand
b) User base their predictions and exepectations about the system on their mental models. Gap between designer’s and user’s mental models need to be decreased trough comuncation of system’s nature to avoid users to make mistakes.

Question 2

What is the diference between functional and structural aspects of mental models?

Answer 2

Functional: users know what to do, but no why
Structural: users know why to do something

Question 3

what is a conceptual model? diference betwenn conceptual model, mental model and system model?

Answer 3

conceptual model: high-level description of how a system is organized and operates, communicated through the interface
Mental model = user’s conceptual model, System model= Programmer’s/Implementation model

Question 4

Describe and explain the seven stagen of action

Answer 4

1. Envision the goal
   — execution—–
2. Prepair a plan
3. Specify the plan
4. Perform
   — evalution —
5. Perceive
6. Interpret
7. Compare

Question 5

Two Major Types of Errors
Mistakes / Slips

Answer 5

Slips: correct goal, but weak execution of action
Mistakes: wrong goal

Question 6

▪ Capture Slip (German: Fangfehler)
▪ Description Slip (German: Beschreibungsfehler)
▪ Mode Error Slip (German: Modusfehler)
▪ Memory-Lapse Slips (German: Aktivierungsverlust, u.a.)

Answer 6

▪ Capture Slip (German: Fangfehler) : Intented action is similar to frequent action. Accidental switch to frequent aciton. (go to uni instead of appointment)
▪ Description Slip (German: Beschreibungsfehler) : Right action on wrong object due object similarity. (zB salt instead sugar)
▪ Mode Error Slip (German: Modusfehler): System in different mode as intended by user. zb( scrolling and drawing on surface)
▪ Memory-Lapse Slips (German: Aktivierungsverlust, u.a.): memory failures related to complete, unnecessearly repeat or get output. (e.g. pay and don’t take the grocessies)

Question 7

• Knowledge-based Mistake
• Rule-based Mistake

Answer 7

• Knowledge-based Mistake: incomplete or incorrect information
• Rule-based Mistake: application of wrong rule in a situation, analogy (e.g. turn more outputs more from tap to thermostat)

Question 8

Recommendations to minimize errors

Answer 8

• add constraints
• make it possible to reverse
• difficult unreversible actions
• make it easy to discover errors

Question 9

• weeknes of dialogs
• better options

Answer 9

• weeknes of dialogs: reduces efficiency, context unclear, if frequently shown user will jsut skip
• better option: modeless feedback (e.g. highlighting color, download iphone)

Question 10

feedforward example

Answer 10

effects of function aplication are visible foward. e.g. instagram filter

Question 11

3 recommendations of good mappings

Answer 11

• consistent
• recognizable or at least quickly learnable
• natual consistent with user’s knowledge

Question 12

4 types of constraints

Answer 12

• physical: e.g. not matching adapter
• logical: e.g. only save after making modifications
• semantic: e.g if you given a glove, even if looks weird, oyu know you can put on your hand
• cultural: e.g. cultural meaning of simbol

Question 13

Affordances and Signifiers

Answer 13

Affordances: perceived possible interactions between people and enviroment (e.g. greyed out)
Signifier: Signal/ Text Description of possible actions