Obstacles and Pitfalls in the Development Path
Gould (1988) has made these general observations about design:
Nobody ever gets it right the first time.
· Development is chock-full of surprises.
· Good design requires living in a sea of changes.
· Making contracts to ignore change will never eliminate the need for change.
· Even if you have made the best system humanly possible, people will still make mistakes when using it.
· Designers need good tools.
You must have behavioral design goals like performance design goals.
The first five conditions listed will occur naturally because people are people, both as users and as developers. These kinds of behavior must be understood and accepted in design. User mistakes, while they will always occur, can be reduced.
Pitfalls in the design process exist because of a flawed design process, including a failure to address critical design issues, an improper focus of attention, or development team organization failures. Common pitfalls are:
· No early analysis and understanding of the user’s needs and expectations.
· A focus on using design features or components that are “neat” or “glitzy.”
· Little or no creation of design element prototypes. o No usability testing.
· No common design team vision of user interface design goals.
· Poor communication between members of the development team.
Designing for People: The Five Commandments
The complexity of a graphical or Web interface will always magnify any problems that do occur. Pitfalls can be eliminated if the following design commandments remain foremost in the designer’s mind.
Gain a complete understanding of users and their tasks: The users are the customers. Today, people expect a level of design sophistication from all interfaces, including Web sites. The product, system or Web site must be geared to people’s needs, not those of the developers.
Solicit early and ongoing user involvement: Involving the users in
design from the beginning provides a direct conduit to the
knowledge they possess about jobs, tasks, and needs. Involvement also allows the developer to confront a person’s resistance to
change, a common human trait. People dislike change for a variety of reasons, among them fear of the unknown and lack of identification with the system.
Perform rapid prototyping and testing: Prototyping and testing the product will quickly identify problems and allow you to develop solutions. Prototyping and testing must be continually performed during all stages of development to uncover all potential defects. If thorough testing is not performed before product release, the testing will occur in the user’s office. Encountering a series of problems early in system use will create a negative first impression in the customer’s mind, and this may harden quickly, creating attitudes that may be difficult to change. It is also much harder and more costly to fix a product after its release.
Modify and iterate the design as much as necessary: While design will proceed through a series of stages, problems detected in one stage may force the developer to revisit a previous stage.. Establish user performance and acceptance criteria and continue testing and modifying until all design goals are met.
Integrate the design of all the system components: The software, the documentation, the help function, and training needs are all important elements of a graphical system or Web site and all should be developed concurrently. Time will also exist for design trade-offs to be thought out more carefully.
The term usability used to describe the effectiveness of human performance. The term usability is defined as “the capability to be used by humans easily and effectively, where,
easily = to a specified level of subjective assessment, effectively = to a specified level of human performance.”
Common Usability Problems
Mandel (1994) lists the 10 most common usability problems in graphical systems as reported by IBM usability specialists. They are:
1. Ambiguous menus and icons.
2. Languages that permit only single-direction movement through a system.
3. Input and direct manipulation limits.
4. Highlighting and selection limitations.
5. Unclear step sequences.
6. More steps to manage the interface than to perform tasks.
7. Complex linkage between and within applications.
8. Inadequate feedback and confirmation.
9. Lack of system anticipation and intelligence.
10. Inadequate error messages, help, tutorials, and documentation.
Some Practical Measures of Usability
· Are people asking a lot of questions or often reaching for a manual?
· Are frequent exasperation responses heard?
· Are there many irrelevant actions being performed?
· Are there many things to ignore?
· Do a number of people want to use the product?
Some Objective Measures of Usability
Shackel (1991) presents the following more objective criteria for measuring usability.
How effective is the interface? Can the required range of tasks be accomplished:
· At better than some required level of performance (for example, in terms of speed and errors)?
· By some required percentage of the specified target range of users?
· Within some required proportion of the range of usage environments?
How learnable is the interface? Can the interface be learned:
· Within some specified time from commissioning and start of user training?
· Based on some specified amount of training and user support?
· Within some specified relearning time each time for intermittent users?
How flexible is the interface? Is it flexible enough to:
· Allow some specified percentage variation in tasks and/or environments beyond those first specified?
· What are the attitudes of the users? Are they: Within acceptable levels of human cost in terms of tiredness, discomfort, frustration, and personal effort?
· Such that satisfaction causes continued and enhanced usage of the system?
The Design Team
Provide a balanced design team, including specialists in:
· Human factors
· Visual design
· Usability assessment
Know your user or client
To create a truly usable system, the designer must always do the following: o Understand how people interact with computers.
· Understand the human characteristics important in design. o Identify the user’s level of knowledge and experience.
· Identify the charac teristics of the user’s needs, tasks, and jobs. o Identify the user’s psychological characteristics.
· Identify the user’s physical characteristics.
· Employ recommended methods for gaining understanding of users.
Why People Have Trouble with Computers
What makes a system difficult to use in the eyes of its user? Listed below are several contributing factors that apply to traditional business systems.
· Use of jargon.
· Non-obvious design.
· Non-obvious design.
· Disparity in problem-solving strategies.
· Design inconsistency.
Responses to Poor Design
Errors are a symptom of problems. The magnitude of errors in a computer-based system has been found to be as high as 46 percent for commands, tasks, or transactions. Errors, and other problems that befuddle one, lead to a variety of psychological and physical user responses.
· Panic or stress.
· Abandonment of the system.
· Partial use of the system.
· Indirect use of the system.
· Modification of the task.
· Compensatory activity.
· Misuse of the system.
· Direct programming.
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