u sability t esting. software quality flexibility adaptability readability testability portability...
TRANSCRIPT
USABILITY
TESTING
Software Quality
Flexibility
Adaptability
ReadabilityTestability
Portability
Reusability
Interoperability
Expandability
Accountability
Understandability
Legibility
Maintainability
Reliability
EfficiencyIntegrity
Correctness
Maturity
Analyzability
Operability
Changeability
Adaptability
Stability
Installability
Replaceability
Learnability
Traceability
Usability
Perform better in demos and reviews, users more receptiveAre easier for first-time users to learn and use, reducing support costs
Characteristics of Usable Products:
Increase corporate user acceptance of internally developed systemsIncrease customer satisfaction and loyalty, increasing product use.
What is Usability ?What is Usability ?
Usability is the “effectiveness, efficiency and satisfaction with which a specified set of users can achieve a specified set of tasks in a particular environment
Usability is the “effectiveness, efficiency and satisfaction with which a specified set of users can achieve a specified set of tasks in a particular environment
ISO Definition:
How easy is it to learn a system ?
How efficiently can the users use the system once they have learned to use it ?
Is the system pleasant to use ?
How frequent are errors made and how serious are they ?
Is it easy to remember what to do ?
Usability Problems ?Usability Problems ?Usability problems are aspects of the user interface that may cause the system to have reduced usability.
Characteristics of the product that make it difficult or unpleasant for users to accomplish tasks supported by the product
Problem Severity:
The frequency with which the problem occurs. Is it common or rare?
The impact of the problem if it occurs. Will it be easy or difficult for the users to overcome?
The persistence of the problems : Is it a one-time event that users can deal with once they know how or will they repeatedly be bothered by the problem?
The market impact. What will the impact be on the popularity of the product?
Usability EvaluationsUsability EvaluationsUser Testing
empirical method of allowing end-users to use the system under monitoring of usability engineers who record the users reactions and problems.
User Testing
empirical method of allowing end-users to use the system under monitoring of usability engineers who record the users reactions and problems.
Usability Inspections
evaluations performed normally by usability specialists (some methods incorporate users and developers) who make a more detailed evaluation of the interface.
Types include: 1. Heuristic Evaluations 2. Pluralistic Walkthroughs 3. Consistency Inspections 4. Standards Inspections 5. Cognitive Walkthroughs
Usability Inspections
evaluations performed normally by usability specialists (some methods incorporate users and developers) who make a more detailed evaluation of the interface.
Types include: 1. Heuristic Evaluations 2. Pluralistic Walkthroughs 3. Consistency Inspections 4. Standards Inspections 5. Cognitive Walkthroughs
User TestingUser Testing
Users performing real task with a real system
Users must be a true representation of the target users
Evaluators video record the users throughout the evaluation and can see what the users are experiencing
Good at finding major problems and task related problems
Users are likely to miss minor problems
Cognitive WalkthroughCognitive Walkthrough
Focus is the ease of learning aspect of usability
Provides limited benefits when compared to other methods
Based on the theory of learning by exploration
Can be used early in the design process
Pluralistic WalkthroughsPluralistic Walkthroughs
Group activity involving developers, users, and human factors specialists work work through scenarios while discussing the usability issues associated with the interface.
Can only evaluate one course of action using the hardcopy medium
Can be used early in design with storyboards or mockups
Standards InspectionsStandards Inspections
Evaluation of an interface to determine compliance with a given standard such as OSF/Motif
Evaluation of an interface to determine compliance with a given standard such as OSF/Motif
Not related to tasks nor scenariosNot related to tasks nor scenarios
Uncovers such things as misplacement of menu items, failure to provide tabbing between groups in dialogue boxes or as in the examples below the misuse of wrong controls
Uncovers such things as misplacement of menu items, failure to provide tabbing between groups in dialogue boxes or as in the examples below the misuse of wrong controls
Misuse of Control Functions:Project Manager insisted that drop-down controls be used to collect information whenever possible due to his fear that some 400,000 corporate users were incapable of typing. The result was the following:
Misuse of Control Functions:Project Manager insisted that drop-down controls be used to collect information whenever possible due to his fear that some 400,000 corporate users were incapable of typing. The result was the following:
Standards Inspections (cont)Standards Inspections (cont)
Misuse of Controls:
In this example the developer should have used a drop-down controls. This type of interface is very inefficient for the user and makes the application slower while using more memory. Makes you wonder how the user would select his country and city?
Misuse of Controls:
In this example the developer should have used a drop-down controls. This type of interface is very inefficient for the user and makes the application slower while using more memory. Makes you wonder how the user would select his country and city?
Consistency InspectionsConsistency Inspections
Evaluation of the consistency across various parts of the product or product family
Distributed and segregated work results in developers making decisions on everything from terminology to placement of icons, window etc
Goal is to have the maximum level of consistency throughout the product or product family so users will be able to quickly learn how to use the system and find using the system easy
OKOK HelpCancel
OKOK
Help
Cancel
OKOK
Help
Cancel
OKOK HelpCancel
How Many Differences Can You Spot ?How Many Differences Can You Spot ?
Answer: Location Boxed OK Underlined H
Answer: Location Boxed OK Underlined H
Heuristic EvaluationHeuristic Evaluation
Guidelines or (Heuristics) used to judge the interface’s usability
One of the “discount usability engineering” methods
Method can be used in early stages of design using storyboards, screen printouts or prototypes
Evaluators inspect the interface on their own
Common HeuristicsCommon Heuristics
Visibility of system status
User control and freedom
Consistency and standards
Help and documentationError prevention
Aesthetic and minimalist design
Flexibility and efficiency of use
Irrelevant information should be deletedIrrelevant information should be deleted
Too much information. Can anyone spot the other error?
Where’s the ‘HELP’ button they say to press?
Common HeuristicsCommon Heuristics
Match between system and the real world
Visibility of system status
User control and freedom
Consistency and standards
Help and documentationError prevention
Aesthetic and minimalist design
Flexibility and efficiency of use
Recognition rather than recall
Geekspeak and System-Orientated TermsGeekspeak and System-Orientated Terms
How would a user know what to select ? Problem using the RGB hexadecimal numbers to represent the colour selection to the user.
This is an Internet Explorer window that lets users set the formatting for headers and footers printed from the browser. I am sure you all know what the sample specifies.
Common HeuristicsCommon Heuristics
Help user recognize, diagnose and recover form errors
Match between system and the real world
Visibility of system status
User control and freedom
Consistency and standards
Help and documentationError prevention
Aesthetic and minimalist design
Flexibility and efficiency of use
Recognition rather than recall
Error Messages Should be MeaningfulError Messages Should be Meaningful
Error Messages Should be MeaningfulError Messages Should be Meaningful
Miscellaneous PointsMiscellaneous PointsGroup vs Individual Evaluators
Individual evaluators have been shown to uncover approximately 35% of the usability errors
Optimum number varies between 3 and 5
What Method Should I Use ?
No single method will find all usability problems
Use a combination of complementary methods
Miscellaneous PointsMiscellaneous Points
When Should I Evaluate
The earlier the better
Iteratively
Developer “Buy-In”
Seeing is believing - Video tape user tests
Incorporate the developer into the evaluation process
What’s in it for Me ?What’s in it for Me ?
Usability problems cost money to fix. The earlier they are discovered the less they cost to fix
A more usable product is a better product and a better product will be better accepted and make more money
If you can’t afford the time and resources to do it rightcan you afford the time and resources do do it over?
ConclusionConclusionUsability is an aspect of Software Quality.
Usability is defined as the ease at which user learn and use the system coupled with the overall experience they have with the product.
Usability problems are problems that adversely effect the usability of the product.
Usability can be assessed by User Testing and Usability Inspection.
The best approach is to use both User testing and Usability Inspections throughout the development cycle to improve the quality of the product