1 These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001 Supplementary Slides for Software Engineering: A Practitioner's Approach, 5/e Supplementary Slides for Software Engineering: A Practitioner's Approach, 5/e copyright © 1996, 2001 R.S. Pressman & Associates, Inc. For University Use Only May be reproduced ONLY for student use at the university level when used in conjunction with Software Engineering: A Practitioner's Approach. Any other reproduction or use is expressly prohibited. This presentation, slides, or hardcopy may NOT be used for short courses, industry seminars, or consulting purposes.

2 These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001 Slide 17 Chapter 15 User Interface Design Chapter 15 at SEPA

3 These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001 Interface Design Easy to use? Easy to understand? Easy to learn?

4 These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001 Interface Design lack of consistency too much memorization no guidance / help no context sensitivity poor response Arcane/unfriendly Typical Design Errors

5 These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001 Golden Rules  Place the user in control  Reduce the user’s memory load  Make the interface consistent

6 These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001 Place the User in Control Define interaction modes in a way that does not force a user into unnecessary or undesired actions.Define interaction modes in a way that does not force a user into unnecessary or undesired actions. Provide for flexible interaction.Provide for flexible interaction. Allow user interaction to be interruptible and undoable.Allow user interaction to be interruptible and undoable. Streamline interaction as skill levels advance and allow the interaction to be customized.Streamline interaction as skill levels advance and allow the interaction to be customized. Hide technical internals from the casual user.Hide technical internals from the casual user. Design for direct interaction with objects that appear on the screen.Design for direct interaction with objects that appear on the screen.

7 These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001 Reduce the User’s Memory Load Reduce demand on short-term memory.Reduce demand on short-term memory. Establish meaningful defaults.Establish meaningful defaults. Define shortcuts that are intuitive.Define shortcuts that are intuitive. The visual layout of the interface should be based on a real world metaphor.The visual layout of the interface should be based on a real world metaphor. Disclose information in a progressive fashion.Disclose information in a progressive fashion.

8 These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001 Make the Interface Consistent Allow the user to put the current task into a meaningful context.Allow the user to put the current task into a meaningful context. Maintain consistency across a family of applications.Maintain consistency across a family of applications. If past interactive models have created user expectations, do not make changes unless there is a compelling reason to do so.If past interactive models have created user expectations, do not make changes unless there is a compelling reason to do so.

9 These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001 User Interface Design Models  System perception — the user’s mental image of what the interface is  User model — a profile of all end users of the system  System image — the “presentation” of the system projected by the complete interface  Design model — data, architectural, interface and procedural representations of the software

10 These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001 User Category  Novices  Knowledgeable, intermittent users  Knowledgeable, frequent users  Often leads to “power-user syndrome” ++

11 These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001 User Interface Design Process

12 These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001 Analysis of User Environment  Where will the interface be located physically?  Will the user sitting, standing, or performing other tasks?  Does the interface hardware accommodate space, light, or noise constraint?  Are there special human factors considerations driven by environmental factors?  to create an analysis model for interface as a basis for design activity ++

13 These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001 Interface design  To define a set of interface objects and actions (and their screen representations) that enable the user to perform all defined tasks that meet every usablility goal defined by the system ++

14 These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001 Implementation  Usually begins with the creation of a prototype  User interface tool kit may be used to complete the construction ++

15 These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001 Validation  Focuses on 1.The ability of the interface  to implement every user task correctly,  to accommodate all task variations, and  to achieve all general user requirements 2.The degree to which the interface is easy to use and easy to learn 3.The user’s acceptance of the interface ++

16 These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001 Task Analysis and Modeling  All human tasks required to do the job (of the interface) are defined and classified  Objects (to be manipulated) and actions (functions applied to objects) are identified for each task  Tasks are refined iteratively until the job is completely defined

17 These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001 Interface Design Activities 1. Establish the goals and intentions for each task. 2. Map each goal/intention to a sequence of specific actions. 3. Specify the action sequence of tasks and subtasks, also called a user scenario, as it will be executed at the interface level. 4. Indicate the state of the system, i.e., what does the interface look like at the time that a user scenario is performed? 5. Define control mechanisms, i.e., the objects and actions available to the user to alter the system state. 6. Show how control mechanisms affect the state of the system. 7. Indicate how the user interprets the state of the system from information provided through the interface.

18 These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001 Design Issues  System response time  Variability: deviation from the average response time  User help facilities  Integrated  Add-on  Error information handling  Command labeling ++

19 These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001 Design Evaluation Cycle

20 These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001 Evaluation criteria  The length and complexity of specification indicates the amount of learning required  The number of tasks and actions per task indicates the interaction time  The number of actions, tasks & system states imply the memory load on users  Interface style, help facilities & error handling indicates the complexity of the interface