Unit-5

• Designing Interface Objects • Software Quality Assurance• System Usability • Measuring User Satisfaction

View Layer: Designing Interface Objects

Identifying view Classes

Designing interface Objects

Objective

To display and obtain needed information in an accessible,efficient manner.

Goal of a User Interface (UI)

The Purpose of a View Layer Interface

User interface can employ one or more Windows

Each window should serve a clear, specific purpose

Intro:

The Purpose of a View Layer Interface (Cont)

Purposes

Forms and data entry windows

Dialog boxes

Application windows

Forms and Data Entry Windows

Data entry windows provide access to data that users can retrieve, display and change in the application.

For example

•Form Design in VB

•Input Dialog boxes in VB

Example for Form Design

Example for Input Box

Forms and Data Entry Windows (Cont)Guidelines for designing Forms and Data Entry Window

Identify the information which we want to display or change

Identify the task that users need to work with data on the form or data entry window

Forms and Data Entry Windows (Cont)

Data entry tasks include Navigating rows in a table, such as moving forward and backward, and going to the first and last record

Adding and deleting rows

Changing data in rows

Saving and canceling the changes

We can provide buttons & menus to initiate the user tasks

Dialog Boxes

Dialog boxes display status information or ask users to supply information or make a decision before continuing with a taskFor example

Message Dialog boxes in VB

OK only

YES NO

Example for Dialog box

Dialog Boxes (Cont)

Guidelines for designing Dialog boxes and Error messages

A dialog box provides an exchange of information or a dialog between the user and the application

Dialog boxes generally appear after a particular Menu item or a Command button pressed

Error message

If we will wrongly enter the date in the entry form then the message show the format for date (DD/MM/YYYY)

Guidelines for the Command Buttons Layout

Position the command buttons are very important

•Bottom

•Align top right

•Align left border is very popular in web interface

Application Windows( Main Window)

An application window is a container of application objects or icons

It contains an entire application with which users can interact

Application Windows (cont)Consist of

Frame or border

Title bar

Scroll bars

Menu bar

Toll bar

Status bar

Example

Application Windows (cont)File menu

Open, Save, Save As, Print, Exit

Edit Menu

Cut, Copy, Paste

View Menu

Zoom,show and etc

Help Menu

Fonts

Colors

Example

Example

Prototyping the user interfaceActivity diagram

Create user interface controls

Associate actions to the users interface controls and their events

Test / Debug

[ No ]

[ Yes ]

VIEW LAYER:DESINGING INTERFACE OBJECTS

Objectives:• Identifying View Class• Designing Interface Objects.

INTRODUCTION

Two types of Interface

1. User Interface

2. Graphical User Interface

The main Goal of UI To display and obtain needed information in an accessible, efficient manner.

The Main Goal of GUIGraphical Representation.

• User Design as a Creative Process

Designing View Layer Classes• An implicit benefit of three layer Architecture.• Separation of the view layer from the business and access layer.

View Objects

Business Objects

Access Objects

View Layer ObjectsThey are the only exposed objects of an application with which users can interact.

View Layer ClassThat represent the set of operations in the business that users must perform to Complete their task,

Ideally in a way they find natural,Easy to remember, and Useful.

The View Layer Objects are represented for two major aspects of the applications.

1. INPUT – Responding to user interaction

2. OUTPUT-Display or Printing business objects.

View Layer Classes is divided four activities • Macro level UI design process.

Identifying view layer objects, User’s perspective.

• Micro level UI design activities.Design axioms and corollaries, Prototyping.

• Testing usability and User satisfaction.• Refining and Iterating the design.

MACRO LEVEL PROCESS

Two Steps:1. For every class identified, determine if the

class interacts with a human actor. 1.Identify the view (interface) objects for the class.

2. Define the relationship among the view objects.

2. Iterate and refine.

MICRO LEVEL PROCESS

The process of designing view objects

1. For every interface object identified in the macro UI design process.

2. Iterate and Refine.

OBJECTIVE

◘ QUALITY ASSURANCE TESTS◘ TESTING STRATEGIES◘ IMPACT OF OBJECT ORIENTATION ON TESTING◘ TEST CASES◘ TEST PLAN◘ CONTINUOUS TESTING◘ MYER’S DEBUGGING PRINCIPLES

QUALITY ASSURANCE TESTS

Why?Computers are infamous for doing what you tell them to do, not necessarily what you want them to do.

Debugging:Is the process of finding out where something went wrong and

correcting the code to eliminate the errors or bugs that cause unexpected results.Types of Errors: Language(syntax) errors Run – time errors Logic errorsCategories: Error – based Testing Scenario(usage) – based Testing

(contd…)

Categories

♠ Error – based Testing.♠ Search for particular clues of interest.♠ Describe how clues should be tested.

♠ Scenario – based Testing.♠ Concentrates on what the user does , not on what

the product does.

(contd…)

TESTING STRATEGIES

BLACK BOX TESTING₤ It is used to represent a system whose inside workings are not available for

inspection.

WHITE BOX TESTING₤ Specific logic is important and must be tested to guarantee the systems

proper functioning.

TOP – DOWN TESTING₤ It supports testing user interface and system integration.

BOTTOM – UP TESTING₤ It starts with the details of the system and proceeds to higher levels by a

progressive aggregation of details until they fit requirements of system.

IMPACT OF OO ON TESTING

٤ Errors.٥ Less Plausible ( not worth testing for )٥ More Plausible ( worth testing for now )٥ New

٤ Impact of Inheritance on Testing.٤ Reusability of tests.

TEST CASES

§ A test case is a set of What – if questions.

§ To test a system you must construct some best input cases, that describe how the output will look.

§ Next, perform the tests and compare the outcome with the expected output.

(contd…)

Myer’s (objective of testing )

ڄ Testing Is a process of executing a program with the intent of finding errors.

ڄ Good test caseThat has a high probability of finding an as – yet – undiscovered error.

ڄ Successful test case That detects an as – yet – undiscovered error.

(Contd…)

Guidelines (for preparing test cases.)

ổ Describe the feature or service.ổ If based on use case, then refer its name.ổ Specify the feature to test and how to test.ổ Test the normal use.ổ Test the abnormal but reasonable use.ổ Test the abnormal and unreasonable use.ổ Test the boundary conditions.ổ While revising document the cases.ổ Reusability and extendibility should be assessed.ổ Add Questions that arise out of previous ones.

Test Plan٭ A Test plan is developed to detect and identify potential problems

before delivering the software to its users.٭ A test plan offers a road map.٭ A dreaded and frequently overlooked activity in software

development.٭ Steps:

§ Objectives of the test.§ Development of a test case§ Test analysis.

٭ Regression Testing.٭ Beta Testing.٭ Alpha Testing. (contd…)

Guidelines (for preparing test plan)

≈ Specify Requirements generated by user.≈ Specify Schedule and resources.≈ Determine the testing strategy.≈ Configuration Control System.≈ Keep the plan up to date.≈ At the end of each milestone, fill routine updates.

CONTINUOUS TESTING

₫ Testing must take place on continuous basis and this refining cycle must continue throughout the development process until you are satisfied with the results.

₫ During this iterative process, prototypes will be transformed incrementally into the actual application.

MYER’S DEBUGGING PRINCIPLES

∂ Bug locating principles.© Think© If you reach an impasse, sleep on it.© If the impasse remains, describe the problem to someone else.© Use debugging tools.© Experimentation should be done as a last resort.

∂ Debugging principles.© Where there is one bug , there is likely to be another.© Fix the error, not just the symptom.© The probability of solution being correct drops down as the size increases.© Beware of error correction, it may create new errors.

System Usability- Introduction

• The task of satisfying user requirements is basic motivation of quality

• Usability testing is different from quality assurance testing in that, rather finding programming defects.

• It reflects the users need and satisfaction

USABILITY TESTING

• Definition:– ISO Defines the usability as the effectiveness,

efficiency and satisfaction with which a specified set of users to can achieve a specified set of tasks.

USABILITY TESTING

• ISO Definition requiresDefining tasks – What are the tasksDefining users – who are the usersA means for measuring effectiveness, efficiency and

satisfaction – how do we measure usability

USABILITY TESTING

• Usability measures the ease of use as well as the degree of comfort and satisfaction users have with the software.

• Usability is one of the most crucial factor so it should begin in the earlier stage of product development.

USABILITY TESTING

• Usability test cases begin with the identification of use cases.

• When designing test focus on use cases and tasks not features.

USABILITY TESTINGOOA-

Use case model

Quality assurance test cases

User satisfactionTest cases

Usability test cases

Test plan

Jacobson’s Life cycle model

Guidelines for Usability testing

• The usability testing should involve all software components

• Usability need not be more expensive or elaborate

• All tests need not involve many subjects• Consider user’s experience as a part of your

software usability• Apply usability testing early and often.

RECORDING THE USABILITY TEST

• When conducting a usability test provide a comfortable environment.

• Record the test results using a video camera or a tape recorder.

• If possible involve all design team members in observing the test and reviewing the results.

USER SATISFACTION TEST

• User satisfaction testing is the process of quantifying the usability test with some measurable attributes of the test such as functionality, cost, or ease of use.

PRINCIPLE OBJECTIVES

• To act as a communication vehicle between users and designers.

• To detect and evaluate changes during the design process.

• To provide a periodic indication of divergence of opinion about the current design.

PRINCIPLE OBJECTIVES (cont…)

• To enable pinpointing specific areas of dissatisfaction for remedy.

• To provide a clear understanding of just how the completed design is to be evaluated.

GUIDELINES FOR DEVELOPING USER SATISFACTI0N TEST

The format of every user satisfaction test is basically the same, but its content is different for each project.

A Custom Form For User Satisfaction Test

10 9 8 7 6 5 4 3 2 1

Ease of use

Functionality

Cost

Intuitive UI

Reliability

Comments

10 9 8 7 6 5 4 3 2 1

10 9 8 7 6 5 4 3 2 1

10 9 8 7 6 5 4 3 2 1

10 9 8 7 6 5 4 3 2 1

Very Easy

Very Functional

Very Inexpensive

Very Intuitive

Very Reliable

Very Hard

Non Functional

Very Expensive

Very Hard to Follow

Not Reliable

I have more to say; I would like to see you

How do you rate the customer tracking project at this time?