Designer yang ikut ambil bagian dalam pengembangan sebuah produk dapat membuat kesalahan tanpa menyadarinya. Sebelum menggunakan atau memasarkan produk, harus mengevaluasi produk dengan cara melakukan percobaan secara terus menerus untuk menemukan error yang terjadi.
Faktor yang menentukan rencana evaluasi :
- stage of design (early, middle, late)
- novelty of project (well defined or exploratory)
- number of expected users
- criticality of the interface ( life-critical medical system vs museum exhibit support)
- costs of product & budget allocated for testing
- time available
- experience of the design and evaluation team
Expert Reviews
Informal
demos can collect useful feedback. Expert
reviews are more formal and more effective. Expert
reviews may need one-half day to one week effort, although can be longer o
explain operational procedures. Can
be scheduled at several points in the development process. Different
experts tend to find different problems. 3-5
expert reviewers can be highly productive. The
expert reviewers must understand task domain, user communities, first-time user
behavior
- Heuristic evaluation
- Guidelines review
- Consistency inspection
- Cognitive walkthrough
- Metaphors of human thinking
- Formal usability inspection
Usability Testing and Laboratories
Usability testing sped up many projects and produced dramatic cost savings. Usability testing is planed to be performed in usability laboratories. Usability lab consist of two 10 by 10 foot areas, one for the participants and another, separated by one-side glass, for the testers and observers. Partisipants represent the user communities, with attention to computer background, task experience, motivation, education, and language ability.
Participation must be voluntary, informed about tasks and operation procedures. informed consent should be obtained. videotaping of performing tasks is reviewed and later shows designers or managers the problems that users encounter. participants must use think-aloud technique. think-aloud is a technique in which participants say aloud what they think.
Survey Instruments
Keys to successful surveys are clear goals in advance and development of focused items that help attain the goals. survey goals can be tied to the components of the Object and Action Interface model of interface design.
User could be asked for their subjective impressions about specific aspects of the interface such as the representation of task domain objects-and-actions and syntax of inputs and design of displays.
Acceptance Test
In a large system, there may be eight or ten such test to carry out on different components of the interface and with different user communities. once acceptance testing has been successful, there may be a period of field testing before national or international distribution
Evaluation During Active Use
Successful active use requires constant attention from dedicated managers, user-services personnel, and maintenance staff. perfection is not attainable, but percentage improvements are possible.
Continuous user-performance data logging
The software architecture should make it easy for system managers to collect data about :
–The patterns of system usage
–Speed of user performance
–Rate of errors
–Frequency of request for online assistance
–A major benefit is guidance to system maintainers in optimizing performance and reducing costs for all participants
Online
or telephone consultants, e-mail, and online suggestion boxes :
Online suggestion box or e-mail trouble reporting :
–Many users feel reassured if they know there is a human assistance available
–On some network systems, the consultants can monitor the user's computer and see the same displays that the user sees.
Online suggestion box or e-mail trouble reporting :
–Electronic mail to the maintainers or designers.
–For some users, writing a letter may be seen as requiring too much effort.
Tidak ada komentar:
Posting Komentar