Usability Testing: Enhancing Software Quality and User Satisfaction

1. USABILITY TESTING

2. Software Quality Flexibility Understandability Adaptability Reliability Replaceability Changeability Portability Analyzability Interoperability Usability Installability Maintainability Maturity Legibility Operability Expandability Stability Readability Learnability Testability Reusability Adaptability Correctness Efficiency Traceability Integrity Accountability

3. How easy is it to learn a system ? How efficiently can the users use the system once they have learned to use it ? Is it easy to remember what to do ? Is the system pleasant to use ? How frequent are errors made and how serious are they ? Characteristics of Usable Products: Perform better in demos and reviews, users more receptive Are easier for first-time users to learn and use, reducing support costs Increase corporate user acceptance of internally developed systems Increase customer satisfaction and loyalty, increasing product use. ISO Definition: 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 What is Usability ?

4. 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: Thefrequencywith which the problem occurs. Is it common or rare? Theimpact of the problem if it occurs. Will it be easy or difficult for the users to overcome? Thepersistence 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 Problems ?

5. 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 Evaluations

6. 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 User Testing

7. Focus is the ease of learning aspect of usability Based on the theory of learning by exploration Can be used early in the design process Provides limited benefits when compared to other methods Cognitive Walkthrough

8. Group activity involving developers, users, and human factors specialists work work through scenarios while discussing the usability issues associated with the interface. Can be used early in design with storyboards or mockups Can only evaluate one course of action using the hardcopy medium Pluralistic Walkthroughs

9. Standards Inspections Evaluation of an interface to determine compliance with a given standard such as OSF/Motif Not 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 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:

10. 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?

11. Distributed and segregated work results in developers making decisions on everything from terminology to placement of icons, window etc Evaluation of the consistency across various parts of the product or product family 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 Consistency Inspections

12. How Many Differences Can You Spot ? OK Cancel Help OK Cancel Help OK Cancel Help OK Cancel Help Answer: Location Boxed OK Underlined H

13. 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 Guidelines or (Heuristics) used to judge the interface’s usability Heuristic Evaluation

14. Error prevention Help and documentation Consistency and standards Visibility of system status User control and freedom Flexibility and efficiency of use Aesthetic and minimalist design Common Heuristics

15. Irrelevant information should be deleted Too much information. Can anyone spot the other error? Where’s the ‘HELP’ button they say to press?

16. Error prevention Help and documentation Consistency and standards Visibility of system status User control and freedom Flexibility and efficiency of use Recognition rather than recall Aesthetic and minimalist design Match between system and the real world Common Heuristics

17. 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. Geekspeak and System-Orientated Terms

18. Error prevention Help and documentation Consistency and standards Visibility of system status User control and freedom Flexibility and efficiency of use Recognition rather than recall Aesthetic and minimalist design Match between system and the real world Help user recognize, diagnose and recover form errors Common Heuristics

19. Error Messages Should be Meaningful

20. Error Messages Should be Meaningful

21. Group 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 Points

22. 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 Miscellaneous Points

23. Usability problems cost money to fix. The earlier they are discovered the less they cost to fix If you can’t afford the time and resources to do it right can you afford the time and resources do do it over? A more usable product is a better product and a better product will be better accepted and make more money What’s in it for Me ?

24. Usability 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 Conclusion