Swe Exam 2 Part 4

Front 1

User Interface Design

Back 1

- should be designed to match skills, experience and expectations of user

Front 2

Human Factors influencing User Interface

Back 2

- Limited Short-Term Memory (7 items of information)
- People Make Mistakes (inappropriate alarms increase stress resulting in more mistakes)
- People are Different (physical capabilities differ; do not just design for your own capabilities)
- People have Different Interaction Preference (some like pictures; some like text)

Front 3

Heuristics of UI Design (10)

Back 3

1) Visibility of System Status (let user know status of sys.)
2) Match between System and the Real World
3) User Control and Freedom (undo & redo buttons)
4) Consistency and Standards (avoid confusing wording)
5) Error Prevention (prevent prob. from occurring)
6) Recognition rather than Recall (use pictures)
7) Flexibility and Efficiency of Use (accelerators-speed up syst. for expert user while still catering to novice)
8) Aesthetic and Minimalist Design (avoid including irrelevant information)
9) Help User Recognize, Diagnose and Recover from Errors
10) Help & Documentation (supply doc. if necessary)

Front 4

Design Issues (2)

Back 4

1) How should info. from user be provided to the computer system?
2) How should info. from th computer syst. be provided to the user?

Front 5

Interaction Styles (5)

Back 5

1) Direct Manipulation
2) Menu Selection
3) Form fill-in
4) Command Language
5) Natural Language

Front 6

Direct Manipulation

Back 6

- Adv: fast, intuitive, easy to learn
- DisAdv: hard to implement, only suitable if there is a visual metaphor for tasks and objects
- Application: video games, CAD systems

Front 7

Menu Selection

Back 7

- Adv: avoids user error, little typing require
- DisAdv: slow for expert users, can become complex
- Application: most general purpose systems

Front 8

Form fill-in

Back 8

- Adv: simple data entry, easy to learn checkable
- DisAdv: takes up a lot of screen-space, causes prob. where user options do not match the form fields
- Application: Stock contol, Personal loan processing

Front 9

Command Language

Back 9

- Adv: powerful and flexible
- DisAdv: hard to learn, poor error management
- Application: Operating Systems, command & control systems

Front 10

Natural Language

Back 10

- Adv: accessible to casual users, easily extended
- DisAdv: requires more typing, unreliable
- Application: information retrieval systems

Front 11

Web Based Interfaces (2)

Back 11

- Many are based on web forms
- Form field can be menus, free text input or radio buttons

Front 12

Information Presentation (5)

Back 12

- Information usually needs to be presented to the user
- The information may be presented directly (text) or transformed (graphical)
- Keep information software and presentation software separate
- Static Information (initial info. that doesn't change)
- Dynamic Info. (info. that changes during session)

Front 13

Information Display Factors (5)

Back 13

- Does user want precise info. or data relationships?
- How quickly do info. values change? & Must change be indicated immediately?
- Must user take action in response to change?
- Is there a Direct Manipulation Interface?
- Is info. textual or numerical? & Are relative values imp.?

Front 14

Digital Presentation

Back 14

- Compact (takes up little screen space)
- Precise values can be communicated

Front 15

Analogue Presentation

Back 15

- Easier to get a quick impression
- Possible to show relative values
- Easier to see exceptional data values

Front 16

Data Visualization (2)

Back 16

- Need to display large amounts of info.
- Reveals relationships between entities and trends in the data

Front 17

Color Display

Back 17

- Adds an extra dimension to an interface and can help the user understand complex info. structures
- Can highlight exceptional events

Front 18

Color Use Guidelines

Back 18

- Limit number of colors used & be conservative
- Use color change to show changes in system status
- Use color coding to support the task that users are trying to perform
- Use color coding in a consistent way
- Be careful with color pairings (red with blue is bad!)
- Be aware of color blindness

Front 19

Error Messages

Back 19

- They are critically important
- Poor messages can mean that a user rejects rather than accepts a system
- Messages should be polite, concise, consistent, and constructive
- Background and experience of users should be the determining factor in message design

Front 20

Design Factors in Message Wording (5)

Back 20

1) Context
2) Experience
3) Skill Level
4) Style
5) Culture

Front 21

User Interface Design Process

Back 21

- It is an iterative process involving communication between users and designers
- 3 Core Activities
- User Analysis (understand users want with syst.)
- System Prototyping (experiment with prototypes)
- Interface Evaluation (let users exp. with prototypes)

Front 22

User Analysis

Back 22

- Understand what users want to do with a system
- Must be described in terms the users and designers can understand
- Use scenarios to describe typical episodes of use

Front 23

UI Requirements (3)

Back 23

- Help user choose appropriate search terms
- Let users select collections to search
- Let users carry out searches and request copies of relevant material

Front 24

Analysis Techniques (3)

Back 24

- Task Analysis ( models steps involved in completing a task)
- Interview and Questionnaires (ask users about the work they do)
- Ethnography (observes the user at work)

Front 25

Interviewing (3)

Back 25

- Design semi-structured interviews based on open-ended questions
- Users can then provide information they think is essential
- Group interviews (allows users to discuss what they do)

Front 26

Ethnography (3)

Back 26

- Involves an external observer questioning workers at work about their work in an unscripted way
- Valuable because many user tasks are difficult to describe/explain
- Helps understand the role of social and org. influences on work

Front 27

UI Prototyping

Back 27

- Goal is to allow users direct experience with the interface
- Without such direct experience it would be impossible to judge the usability of an interface
- 2 Stages to Prototyping
1) Paper prototyping (early in process)
2) The design is then refined (made more sophisticated)

Front 28

Paper Prototyping (3)

Back 28

- Work through scenarios using sketches of the interface
- Use a storyboard to present a series of interactions with the system
- It's an inexpensive and effective way to get user reactions

Front 29

Prototyping Techniques (3)

Back 29

1) Script-driven (develop scripts using SW)
2) Visual Programming (use a language designed for rapid development)
3) Internet-based (use a web browser and associated scripts)

Front 30

Usability Attributes (5)

Back 30

1) Learnability
2) Speed of Operation
3) Robustness
4) Recoverability
5) Adaptability

Front 31

Evaluation Techniques (4)

Back 31

1) Questionnaires
2) Video recording and evaluation of system use
3) Instrumenting code to collect info. on user errors
4) Code the SW to collect on-line user feedback

Front 32

Design Principles (6)

Back 32

1) User Familiarity (base interface on user-oriented terms and concepts)
2) Consistency (commands and menus should have same format)
3) Minimal Surprise (user should be able to predict the operation of comparable commands)
4) Recoverability (resilience to user errors allowing user to undo actions)
5) User Guidance (supply help systems or manuals)
6) User Diversity (should facilitate different types of users)