Interaction Design I

Saffer, D. (2007) Designing for Interaction. Berkeley: New Riders. [chapters 1, 2, 3]

Interaction design: designing the behavior of product and services, i.e. how it works
Historically, interaction design emerged as product design shifted focus from 'engineering' to 'designing'. This is in alignment with the technological sophistication where as the computers became more capable, more attention could be put into the issues of usability.

4 approaches to design:
user-centered design - focus on user's needs and goal
activity-centered design - focus on acitivities or tasks to be accomplished through the system
systems design - focus on components of the system, useful for seeing the big picture
genius design - focus on the designer's ability

Elements of interaction design:
motion, space, time (rhythm), appearance, texture, sound

Laws of Interaction Design
Moore's Law - Intel guy hypothesizing that processing power will double every year
Fitt's Law - larger the target, faster it can be pointed to
Hick's Law - faster the choice of navigation if lesser number of choice available
Magical number seven - George Miller's identification of working memory limitation ranging 7 +/- 2 chunks
Tesler's Law of the Conservation of Complexity: tasks have inherent complexity
Poka-Yoke Principle - putting constraints to minimize error as soon as possible
Direct and Indirect Manipulation
Feedback and Feedforwrad

Characteristics of Good Interaction Design
Trustworthy, appropriate, smart (sharing cognitive load), responsive, clever (delightful intelligence), ludic (playful), pleasurable

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Shedroff (1999). Information Interaction Design: A Unified Field Theory of Design. In Jacobsen, R. (Ed.), Information Design, pp. 267–292. Cambridge, MA: MIT Press.

data - information - knowledge - wisdom
The distinction between them probably comes from information technology field where it is necessary to identify the characteristics associated with different level of 'organization'. It is interesting to see how cognitive psychologists do not make such distinctions and they almost feel it unnecessary. This might be because the distinction really comes from the perspective of people that manipulate meaning for presentation (provider), while the psychologists come from the perspective of the meaning making (receiver). In this sense, it is rather problematic when Shedroff says that knowledge can be affected directly by the designers...Information can indeed be directly manipulated but knowledge is constructed 'actively' by the perceiver, through their selective attention, perception and organization, in that there really is no way we can 'directly' influence the process.

the continuum of interactivity
feedback; control; creativity;productivity;communications;adaptivity
defines the level of interactivity from passive to active participation by the users. It is interesting that the author notes, it is not always desired to provide the most interactivity, this depends on the goal of design. (defying the assumption that more interactivity is better)


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Shneiderman, B. & Plaisant, C. (2005). Designing The User Interface. Chapter 2: Guidelines, Principles, and Theories (pp. 60–106). Boston: Pearson.

guidelines - principles - theories
at different levels, they serve different purposes by informing designers with differing specificity and understanding.

Guidelines provide specific rules that can be readily applied in design practice, however, due to their specificify, might not apply to all cases.
- Navigation
- organization of the display
- managing attention
- data entry
few principles keep coming up throughout the guidelines: consistency (theoretical explanation: easy to learn & maintain), sufficient user control, non-distracting

Pinciples
Good balance of attention between individual difference and universality is needed in consideration of their skill, preference, task

8 golden rules of interaction design
1. strive for consistency (managing expectation)
2. cater to universal usability
3. offer informative feedback
4. Design dialogs to yield closure (satisfaction of experience)
5. Prevent errors
6. permit easy reveral of actions
7. Support internal locus of control (especially for experienced users; balance between automation and control)
8. Reduce short-term memory load

Theories
cognitive theories inform how users process information the cognitive task demands.
Taxonomies to categorize tasks, preference etc.

levels of analysis
- conceptual level
- semantic level
- syntactic level
- lexical level
The distinction appears to be more of categorization (of information) rather than the pure sense of level (i.e. hierarchical leveling). Also, the distinction is outdated due to the fact that the levels were based on command line interface (c.f. modern GUI)

Stages-of-action models
Based on user interaction with tools (Norman)
Forming the goal - forming the intention - specifying the action - executing the action - perceiving the system state - interpreting the system state - evaluating the outcome
The model fits well in identification of
- gulf of execution (user's intention vs allowed action)
- gulf of evaluation (user's expectation vs feedback)

GOMS model (Card, Moran, Newell)
goals - operators - methods - selection rules
keystroke level model - simplified version of GOMS predicting the error-free expert performance of achieving the goal

Action Grammar (Reisner) -> Task Action Grammar (Payne & Greene)
outline multiple levels of consistency

OAI model (Object Action Interface)
Task, interface hierarchical models