Software Engineering 2 - Lecture 3

User experience design

Ensure that no aspect of your software appears the final product without the explicit decision of stakeholders to include it.

Strategy
Scope
Structure
Skeleton
Surface

User Experience Design Elements:

Strategy

Identifies user needs and customer business goals that form the basis for all UX design work.

Scope

Includes both the functional and content requirements needed to realize a feature set consistent with the project strategy.

Structure

Consists of the interaction design [For example, how the system reacts in response to user action] and information architecture.

Skeleton

Comprised of three components: information design, interface design, navigation design.

Surface

Presents visual design or the appearance of the finished project to its users.

Interaction design

Focuses on interface between product and user.

User interface

The purpose of this is to present just enough information to help the users decide what their next action should be to accomplish their goal and how to perform it.

Usability engineering

Part of UX design work that defines the specification, design, and testing of the human-computer interaction portion of a software product.

Accessibility

The degree to which people with special needs are provided with a means to perceive, understand, navigate, and interact with computer products.

Visual design

An artistic endeavor that complements the technical aspects of the user experience design.

Place User in Control
Reduce User’s Memory Load
Make Interface Consistent

Golden Rules

Golden Rule 1: Place User in Control

Define interaction modes in a way that does not force a user into unnecessary or undesired actions.

Golden Rule 2: Reduce User’s Memory Load

Reduce demand on short-term memory. Establish meaningful defaults. Define shortcuts that are intuitive.

Golden Rule 3: Make Interface Consistent

Allow the user to put the current task into a meaningful context. Maintain consistency across a family of applications.

User model
Design model
Mental model
Implementation model

User Interface Design Models

User model

A profile of all end users of the system.

Design model

A design realization of the user model.

Mental model

The user’s mental image of what the interface is.

Implementation model

The interface “look and feel” coupled with supporting information that describe interface syntax and semantics.

Interface analysis

Focuses on the profile of the users who will interact with the system.

Interface design

Defines a set of interface objects and actions that enable a user to perform all defined tasks in a manner that meets every usability goal defined for the system.

Interface construction

Normally begins with the creation of a prototype that enables usage scenarios to be evaluated.

Interface validation

It focuses on the ability to implement every user task correctly, degree to which interface is easy to learn and use, the user’s acceptance of the interface as a tool in here work.

Anticipation

An application should be designed so that it anticipates the user’s next move.

Communication

The interface should communicate the status of any activity initiated by the user.

Consistency

The use of navigation controls, menus, icons, and aesthetics should be consistent throughout.

Controlled Autonomy

The interface should facilitate user movement throughout the application, but it should do so in a manner that enforces navigation conventions that have been established for the application.

Efficiency

The design of the application and its interface should optimize the user’s work efficiency.

Flexibility

The interface should be flexible enough to enable some users to accomplish tasks directly and others to explore the application in a somewhat random fashion.

Focus

The interface (and the content it presents) should stay focused on the user task(s) at hand.

Human Interface Objects

A vast library of reusable human interface objects has been developed for both Web and mobile apps. Use them.

Latency Reduction

Rather than making the user wait for some internal operation to complete the application should use multitasking in a way that lets the user proceed with work as if the operation has been completed.

Learnability

An application interface should be designed to minimize learning time and, once learned, to minimize relearning required when the app is revisited.

Metaphors

An interface that uses this is easier to learn and easier to use, as long as the metaphor is appropriate for the application and the user.

Readability

All information presented through the interface should be readable by young and old.

Track State

When appropriate, the state of the user interaction should be tracked and stored so that a user can log off and return later to pick up where he left off.

Visible Navigation

A well-designed interface provides the illusion that users are in the same place, with the work brought to them.

Application Accessibility

Software engineers must ensure that interface design encompasses mechanisms that enable easy for people with special needs.

Response Time

System response time has two important characteristics: length and variability. Aim for consistency to avoid user frustration.

Help Facilities

This should be provided to enable a user to get a question answered or resolve a problem without leaving the interface.

Error Handling

Every error message or warning produced by an interactive system should: use user understandable jargon, provide constructive error recovery advice, identify negative consequences of errors, contain an audible or visual cue, and never blame user for causing the error.

Menu and Command Labeling

The use of window-oriented, point-and-pick interfaces has reduced reliance on typed commands. Ensure every menu option has a command version, make commands easy for users to type, remember, allow for command abbreviation, labels are self-explanatory, sub-menus match style of master menu items, and command conventions work across the family of applications.

Internationalization

Software engineers and their managers invariably underestimate the effort and skills required to create user interfaces that accommodate the needs of different locales and languages.