人机交互的高精度和低精度原型

High-Fidelity or Low-Fidelity when prototyping for Human-Computer Interaction

Interaction Design
Interactive products in everyday use
Supporting people in their everyday and working lives
Cell phones, computer, ATM, laundry machine, VCR...
Are they easy, effortless and enjoyable to use?
Key points
Interaction Design involves taking into account a number ofinterdependent factors including context of use, type of task and kindof user
Need to strive for usability and user experience goals
Conceptual Model

The DESIGNER has model of how the system should work.
The USER creates a model of how he/she thinks the system works.
The SYSTEM has an image of how it actually works. In an ideal world,all three should map into each other and the user’s mental model of thesystem should be equal to the designer’s mental model. That wouldprovide good usability and effective interaction.
The Interaction Design Process

Prototyping goals
While a usable product is a system where the image ofit provides a user mental model which is equal to the designer mentalmodel, it natural to compare these models. That can be done usingprototyping.
Depending on the product that is developing the designer first haveto create a brief idea what kind of feedback that is desired from theprototyping process.
Low-Fidelity

Does not look very much like the final product. Material, behavior etc.
Material such as paper & cardboard rather than electronic screens, metal and detailed code.
Simple, cheap & quick to produce and redesign. Encourage further exploration of alternative designs and ideas.
Early stage of development –prototyping for the conceptual design.
High-Fidelity
Looks very much like the final product.
If the prototype is for software system, a software tool, such asMacromedia Director or Flash, Visual Basic or Smalltalk, might beneeded.
Software prototype tools are also often qualified development environments.
More time-consuming to produce than low-fidelity prototyping.
Low-Fidelity Advantages & Disadvantages
Advantages
Low-fidelity representations, such as sketches, differ from the finalproduct in interaction design, visual appearance, and/or level ofdetails. The method is quick & cheap which encourage iterativedesign idea tryouts between/during usability tests.
Quick Low-fidelity tests allows designers and users to focus onhigh-level interaction design and information architecture, rather thanon details or visual style.
Disadvantages
Users might judge a low-fidelity prototype as unprofessional.
While Low-fidelity prototypes allow spontaneous changes for exploring interactions, they also sacrifice some realism.
Limitations in navigation and flow while a control person has to “make the interaction”.
High-Fidelity     Advantages & Disadvantages
Advantages
High-fidelity prototypes offer more realistic interactions than low-fidelity.
Better at conveying the range of design possibilities.
User-driven.
Disadvantages
High-fidelity prototyping may make designers reluctant tochange designs and less likely to fully explore the design space.
Take a long to build and requires skill.
Reviewers and testers tend to comment on surface aspects rather than content.
Conclusion
Low-fidelity prototypes have big advantages in costand ease of iteration, and allow designers to focus on interactiondesign and information architecture rather than aesthetic details.
Prototyping on paper eases testing of alternative design and enables testing in a more exploratory, dynamic way.
Computer prototypes allow automatic recording of user tests, can bedistributed electronically, and can help document the design process.
What kind of prototype method to choose is not a simple decision. Docombine and apply several techniques might be a good idea.
References
nstitute for Personalized Information Environment. 1995. FRIEND21 Human Interface Architecture Guidelines.
orman, D.A. 1988. The Psychology of everyday things. Basic Books.
8nyder C. 2003. Paper prototyping. Morgan Kaufmann.
reece, Rogers, Sharp. 2002. Interaction Design beyond human-computer interaction.