CHAPTER 14: Designing Interfaces and Dialogues 14.1 MSIS 5653 Advanced Systems Development Dursun Delen, Ph.D. Department of Management Oklahoma State University

D. Delen MSIS 5653 – Advanced Systems Development Learning Objectives Understand the process of designing interfaces and dialogues and the deliverables Contrast and apply several methods for interacting with a system List and describe various input devices and discuss usability issues for each in relation to performing different tasks Discuss the general guidelines for interface design including: Layout and design Structuring data entry fields Providing feedback System help 14.2

D. Delen MSIS 5653 – Advanced Systems Development Learning Objectives Discuss the design of human-computer dialogues and the use of dialogue diagramming Design graphical user interfaces Understand interface design guidelines unique to the design of Internet based electronic business systems 14.3

D. Delen MSIS 5653 – Advanced Systems Development Designing Interfaces in SDLC 14.4

D. Delen MSIS 5653 – Advanced Systems Development Introduction Interface? Focus of user interface design is to determine how information is provided to and captured from the users Dialogues are analogous to a conversation between two people A good human-computer interface provides a unifying structure for finding, viewing and invoking the different components of a system 14.5

D. Delen MSIS 5653 – Advanced Systems Development The Process of Designing Interfaces and Dialogues User-focused activity Conducted in parallel to form and report design processes Employs prototyping methodology 1.Collect information 2.Construct prototype 3.Assess usability 4.Make refinements 14.6

D. Delen MSIS 5653 – Advanced Systems Development The Process of Designing Interfaces and Dialogues Deliverables Design Specifications  Narrative  Sample Design  Testing and usability assessment 14.7

D. Delen MSIS 5653 – Advanced Systems Development Interaction Methods and Devices Methods of Interacting Command Language Interaction  Users enter explicit statements into a system to invoke operations  Pros / Cons? Menu Interaction  A human computer interaction method  A list of system options is provided  A specific command is invoked by user selection of a menu option  Menu complexity varies according to needs of system and capabilities of development environment 14.8

D. Delen MSIS 5653 – Advanced Systems Development Guidelines for Designing Menus Methods of Interacting Menu Interaction (Continued…)  Menu Design Guidelines Wording Organization Length Selection Highlighting  Two common placement methods Pop-up Drop-down  Hierarchies can be employed

D. Delen MSIS 5653 – Advanced Systems Development Sample Menu Designs

D. Delen MSIS 5653 – Advanced Systems Development Types of Menu Configurations

D. Delen MSIS 5653 – Advanced Systems Development Pop-Up and Drop-Down Menus

D. Delen MSIS 5653 – Advanced Systems Development Building Menus with Advanced Tools

D. Delen MSIS 5653 – Advanced Systems Development Interaction Methods and Devices Methods of Interacting Form Interaction  Allows users to fill in the blanks when working with a system  Measures of an effective design Self-explanatory title and field headings Fields organized into logical groupings Distinctive boundaries Default values Displays appropriate field lengths Minimizes the need to scroll windows

D. Delen MSIS 5653 – Advanced Systems Development Example: Form Interaction

D. Delen MSIS 5653 – Advanced Systems Development Interaction Methods and Devices Methods of Interacting Object-Based Interaction  Symbols are used to represent commands or functions  Icons Graphic symbols that look like the processing option they are meant to represent Use little screen space Can be easily understood by users Natural Language Interaction  Inputs to and outputs from system are in a conventional speaking language like English

D. Delen MSIS 5653 – Advanced Systems Development Interaction Methods and Devices Hardware Options for System Interaction List of devices  Keyboard  Mouse  Joystick  Trackball  Touch Pad  Touch Screen  Light Pen  Graphic Tablet  Voice  Carpal Tunnel Syndrome ?

D. Delen MSIS 5653 – Advanced Systems Development Interaction Methods and Devices Hardware Options for System Interaction Usability assessment research for various devices 14.18

D. Delen MSIS 5653 – Advanced Systems Development Designing Interfaces Designing Layouts Standard formats similar to paper-based forms and reports should be used Screen navigation on data entry screens should be left-to- right, top-to-bottom as on paper forms 

D. Delen MSIS 5653 – Advanced Systems Development Designing Layouts Flexibility and consistency are primary design goals Users should be able to move freely between fields Data should not be permanently saved until the user explicitly requests this Each key and command should be assigned to one function 14.20

D. Delen MSIS 5653 – Advanced Systems Development Structuring Data Entry Entry Never require data that are already on-line or that can be computed Defaults Always provide default values when appropriate Units Make clear the type of data units requested for entry Replacement Use character replacement when appropriate Captioning Always place a caption adjacent to fields Format Provide formatting examples Justify Automatically justify data entries Help Provide context-sensitive help when appropriate 14.21

D. Delen MSIS 5653 – Advanced Systems Development Controlling Data Input One objective of interface design is to reduce data entry errors Role of systems analyst is to anticipate user errors and design features into the system’s interfaces to avoid, detect and correct data entry mistakes Data entry errors Appending Truncating Transcripting Transposing 14.22

D. Delen MSIS 5653 – Advanced Systems Development Controlling Data Input – Cont. Techniques used by system designers to detect errors Class/Composition (type) Combinations Expected Values Missing Data Pictures/Templates (format) Range Reasonableness Size Values

D. Delen MSIS 5653 – Advanced Systems Development Providing Feedback 1. Status Information Keeps users informed of what is going on with the system Displaying status information is especially important if the operation takes longer than a second or two 2. Prompting Cues Best to keep as specific as possible Ready for Input: ____ vs. Enter SSN (xxx-xx-xxxx): _____ 3. Error and Warning Messages Messages should be specific and free of error codes User should be guided toward a result Use terms familiar to user Be consistent in format and placement of messages 14.24

D. Delen MSIS 5653 – Advanced Systems Development Providing Help Place yourself in user’s place when designing help Guidelines Simplicity  Help messages should be short and to the point Organization  Information in help messages should be easily absorbed by users Demonstrate  It is useful to explicitly show users how to perform an operation Context-Sensitive Help Enables user to get field-specific help Users should always be returned to where they were when requesting help 14.25

D. Delen MSIS 5653 – Advanced Systems Development Providing Help 14.26

D. Delen MSIS 5653 – Advanced Systems Development Designing Dialogues Dialogue Sequence in which information is displayed to and obtained from a user Primary design guideline is consistency in sequence of actions, keystrokes, and terminology Three step process 1.Design dialogue sequence 2.Build a prototype 3.Assess usability 14.27

D. Delen MSIS 5653 – Advanced Systems Development Designing the Dialogue Sequence Define the sequence Have a clear understanding of the user, task, technological and environmental characteristics Dialogue Diagram A formal method for designing and representing human- computer dialogues using box and line diagrams Consists of a box with three sections 14.28

D. Delen MSIS 5653 – Advanced Systems Development Designing the Dialogue Sequence PVF Customer Information System

D. Delen MSIS 5653 – Advanced Systems Development Building Prototypes and Assessing Usability Often optional activities Task is simplified by using graphical design environment 14.30

D. Delen MSIS 5653 – Advanced Systems Development Designing Interfaces and Dialogues in Graphical Environments Interface Design Issues 1.Become an expert user of the GUI environment  Understand how other applications have been designed  Understand standards 2.Gain an understanding of the available resources and how they can be used  Become familiar with standards for menus and forms  Standards for menus (see next page >>>)  Some common properties of windows and forms in a GUI environment: Modality Resizable Movable Maximize/Minimize 14.31

D. Delen MSIS 5653 – Advanced Systems Development Standards for Menus

D. Delen MSIS 5653 – Advanced Systems Development Designing Interfaces and Dialogues in Graphical Environments Dialogue Design Issues Goal is to establish the sequence of displays that users will encounter when working with system Ability of some GUI environments to jump from application to application or screen to screen makes sequencing a challenge One approach is to make users always resolve requests for information before proceeding Dialogue diagramming helps analysts better manage the complexity of designing graphical interfaces Wizard type screens are useful 14.33

D. Delen MSIS 5653 – Advanced Systems Development Designing Interfaces and Dialogues for Electronic Commerce Applications General Guidelines Design errors  Opening new Browser Window  Breaking the Back Button  Complex URLs  Orphan Pages  Scrolling Navigation Pages  Lack of Navigation Support  Hidden Links  Links that Don’t Provide Enough Information  Buttons that Don’t Provide Click Feedback 14.34

D. Delen MSIS 5653 – Advanced Systems Development Summary Interaction Methods and Devices Design guidelines for interfaces Layout design Structuring data entry fields Providing feedback Designing help Designing dialogues Designing interfaces and dialogues in graphical environments Designing Interfaces and Dialogues for Web Application 14.35

CHAPTER 15: Finalizing Design Specifications

D. Delen MSIS 5653 – Advanced Systems Development Learning Objectives Discuss the need for system design specifications Define quality requirements and write quality requirements statements Read and understand a structure chart Distinguish between evolutionary and throwaway prototyping Explain the role of CASE tools in capturing design specifications Demonstrate how design specifications can be declared for Web-based applications

D. Delen MSIS 5653 – Advanced Systems Development Finalizing Design Specifications in SDLC

D. Delen MSIS 5653 – Advanced Systems Development Introduction There is a need for systems to be developed more quickly today The lines between analysis and design and design and implementation are blurring Traditional approaches allowed for a break between design and implementation Other approaches, such as CASE and prototyping, have caused overlap between the two phases

D. Delen MSIS 5653 – Advanced Systems Development The Process of Finalizing Design Specifications Less costly to correct and detect errors during the design phase Two sets of guidelines Writing quality specification statements The quality of the specifications themselves Quality requirement statements Correct Feasible Necessary Prioritized Unambiguous Verifiable

D. Delen MSIS 5653 – Advanced Systems Development The Process of Finalizing Design Specifications Quality requirements Completely described Do not conflict with other requirements Easily changed without adversely affecting other requirements Traceable back to origin

D. Delen MSIS 5653 – Advanced Systems Development The Process of Finalizing Design Specifications Deliverables and Outcome Set of physical design specifications  Contains detailed specifications for each part of the system

D. Delen MSIS 5653 – Advanced Systems Development Representing Design Specifications Traditional Methods Pre-CASE Documents written natural language and augmented with graphical models Specification documents  Figure 15-2 shows an example >>>  Several methods for streamlining Computer-based requirements management tools Prototyping Visual development environments

D. Delen MSIS 5653 – Advanced Systems Development Example Specification Document …

D. Delen MSIS 5653 – Advanced Systems Development Representing Design Specifications Structure Charts Shows how an information system is organized in hierarchical models Shows how parts of a system are related to one another Shows breakdown of a system into programs and internal structures of programs written in third and fourth generation languages

D. Delen MSIS 5653 – Advanced Systems Development Representing Design Specifications Structure Charts Module  A self-contained component of a system, defined by a function (sections in COBOL, subroutines in FORTRAN)  One single coordinating module at the root of structure chart (a.k.a. boss)  Communicate with each other by passing parameters Data couple: A diagrammatic representation of the data exchanged between two modules in a structure chart Flag: A diagrammatic representation of a message passed between two modules

D. Delen MSIS 5653 – Advanced Systems Development Representing Design Specifications Special Symbols used in Structure Charts 1.Diamond (conditional call of subordinates)  Only one subordinate will be called 2.Curved Line (repetitive calls of subordinates)  Subordinates are called repeatedly until terminating condition is met 3.Predefined modules 4.Embedded module (Hat)  Subordinate module is important logically but code is contained in superior module

D. Delen MSIS 5653 – Advanced Systems Development Example: Structured Chart

D. Delen MSIS 5653 – Advanced Systems Development Representing Design Specifications Structure Charts Pseudocode  Method used for representing the instructions inside a module  Language similar to computer programming code  Serves for two functions Helps analyst think in a structured way about the task a module is designed to perform Acts as a communication tool between analyst and programmer 15.49

D. Delen MSIS 5653 – Advanced Systems Development Representing Design Specifications Prototyping Construction of the model of a system Allows developers and users to  Test aspects of the overall design  Check for functionality and usability Two types 1. Evolutionary Prototyping 2. Throwaway Prototyping 15.50

D. Delen MSIS 5653 – Advanced Systems Development Representing Design Specifications Prototyping Evolutionary Prototyping  Begin by modeling parts of the target system  If successful, evolve rest of the system from the prototype  Prototype becomes actual production system  Often, difficult parts of the system are prototyped first  Exception handling must be added to prototype 15.51

D. Delen MSIS 5653 – Advanced Systems Development Representing Design Specifications Prototyping Throwaway Prototyping  Prototype is not preserved  Developed quickly to demonstrate unclear aspect of system design  Fast, easy to use development environment aids this approach 15.52

D. Delen MSIS 5653 – Advanced Systems Development A Prototyping Example with Oracle: HB Inventory Control System 1. Transforming and Generating the Database Entity-Relationship Diagramming Tool

D. Delen MSIS 5653 – Advanced Systems Development A Prototyping Example with Oracle: HB Inventory Control System 1. Transforming and Generating the Database Database Design Transformer Tool

D. Delen MSIS 5653 – Advanced Systems Development A Prototyping Example with Oracle: HB Inventory Control System 1. Transforming and Generating the Database Server Model Diagram Data Definition Language (DDL) script

D. Delen MSIS 5653 – Advanced Systems Development A Prototyping Example with Oracle: HB Inventory Control System 2.Transforming and Generating Software Modules Functional Hierarchy Diagram

D. Delen MSIS 5653 – Advanced Systems Development A Prototyping Example with Oracle: HB Inventory Control System 2.Transforming and Generating Software Modules Module Diagram for Update Inventory Added Function Application Design Transformer

D. Delen MSIS 5653 – Advanced Systems Development A Prototyping Example with Oracle: HB Inventory Control System 2.Transforming and Generating Software Modules Generated Form in Design Editor

D. Delen MSIS 5653 – Advanced Systems Development Radical Methods: eXtreme Programming Developed by Kent Beck (2000) It is distinguished by its Short Cycles Incremental Planning Approach Focus on automated tests Utilizes a two-person programming team Planning, analysis, design and construction are fused together into one phase Requirements and specifications are uniquely captured 15.59

D. Delen MSIS 5653 – Advanced Systems Development Planning game Players  Business  Development Story cards  Description of procedure or system feature Radical Methods: eXtreme Programming

D. Delen MSIS 5653 – Advanced Systems Development Planning game Radical Methods: eXtreme Programming

D. Delen MSIS 5653 – Advanced Systems Development Iteration Planning Game Played by programmers Task Cards  Several task cards generated for each story card  Three phases Exploration Story cards converted to task cards Commitment Programmers accept responsibility for tasks Steering Programmers write code, test it and integrate it  Game takes place during time between intervals of planning game steering phase meetings Radical Methods: eXtreme Programming

D. Delen MSIS 5653 – Advanced Systems Development Radical Methods: RAD Four life-cycle phases Planning Design Construction Cutover Iteration between design and construction 15.63

D. Delen MSIS 5653 – Advanced Systems Development Electronic Commerce Application Microsoft FrontPage can be used to build throwaway prototypes Template based HTML for Rapid development Consistency in  Look an feel  Functionality  Navigation 15.64

D. Delen MSIS 5653 – Advanced Systems Development Summary Types of Design Specifications Written document augmented by various diagrams Structure chart Computer-based requirements management tool Prototypes  Throwaway versus Evolutionary Radical Methods eXtreme Programming RAD Electronic Commerce Application Throwaway prototyping 15.65