Fidelity is defined in a number of ways in the literature and the debate in this forum is reminiscent of the debate about low versus hi fidelity that has been going on for about 20 years. The major questions that show up in the debates include:
How do you define fidelity? What are the dimensions of fidelity? When is low-fidelity preferred over high fidelity? What are the major problems with both low and high fidelity prototypes? Can you find the same usability problems using low-fidelity and high-fidelity prototypes? (More recently, here and in Bill Buxton's new work) Are sketches prototypes? Here are a few definitions and some of the articles and books that discuss issues around fidelity and prototyping. Arnowitz, Arent, & Berger (2007) have published an excellent and detailed book that describes a range of prototyping methods including card sorting (prototyping the information structure), Wizard of OZ prototyping, wireframes, paper prototypes, storyboards, coded prototypes, blank model prototypes, and video prototypes. Each chapter describes a process and the issues with various prototyping methods. Arnowitz and his colleagues refer to 6 levels of fidelity: - Information design fidelity - Interaction design fidelity - Visual design fidelity - Editorial fidelity - Branding expression - System performance Some other definitions: • Tullis (1990) Fidelity is the degree to which a prototype represents the appearance and interaction of the product. • Virzi (1989) "To the extent that a person using a prototype cannot distinguish it from the final system, the prototype is high fidelity. If the prototype can readily be distinguished from the service, then fidelity is low." (Virzi, p. 224) • Nielsen (1989) uses the concept of vertical versus horizontal prototypes (bread versus depth of functionality) • Virzi, Sokolov, & Karis (1996) Four primary dimensions of fidelity: breadth of features, degree of functionality, similarity of interaction, and aesthetic refinement. Another view of the dimensions of prototyping from the work of Houde and Hill in the 1997 Handbook of HCI involves three "dimensions" or questions that various types of prototypes can answer: Look & Feel (What is it like to look at and interact with the product?), Role (What can this product do for the user?), and "Implementation (How can the product be made to perform its functions?). Houde and Hill give a large number of examples of protoytpes that fall at different places on these 3 dimensions (they use a triangle to illustrate this in their article). For example, a "storyboard" could be a powerful way to prototype the role of the product (what can this product do for the user?), but not very useful on Implementation or look & feel. The premise behind the Houde and Hill article is that a portfolio of prototypes can examine each of these questions or areas (Arnowitz and colleagues also take that approach). Similarly, a developer might write code to test the performance of something like a new search feature in the actual code with no UI and this would be at the extreme of the implementation end though the testing might influence the UI depending on potential performance issues. Some other "dimensions of prototyping that don't come up as much as fidelity include: - Ownership - Discardibility - Support required for creation and evaluation - Ease of change - Degree of user involvement (GOMS can be considered a way to prototype system performance or compare two designs, but it doesn't require any users versus other methods that do require users). - Integration with other tools Tom Erickson (1995) classified prototypes into two categories: vision prototypes (which could be high-aesthetic fidelity interactive prototypes like the Apple Knowledge Navigator vision prototype (1988) . Erickson and others have noted that rough paper sketches may not be powerful enough to get funding to work on a real project, but there is also the danger that slick vision prototypes like the Apple Knowledge Navigator video can result in inappropriate expectations (which occurred with the Apple video). The terminology for prototypes varies a lot between companies with the exact same thing called a "mockup" in one company and a "paper prototype" in another. Wireframes can range from roughed out block diagrams to pixel-performance high-gloss images for example. So, what I get from reading through the debates here and in the literature is that there are a number of dimensions of fidelity and various combinations of levels of fidelity are required to answer different questions (and to get funding) and different levels of fidelity can be used throughout the product design process. You can also have hybrid prototypes that mix working prototypes with paper or video for example. Chauncey Some research on the fidelity issue can be found at: http://guir.berkeley.edu/projects/fidelity/pubs/Walker_HFES_2002.htm On Nov 11, 2007 8:03 AM, Todd Zaki Warfel <[EMAIL PROTECTED]> wrote: > How do you define lo-fi and hi-fi? > > Let's take an on-line banking application, for example. What's the lo- > fi prototype? What's the hi-fi prototype? ________________________________________________________________ *Come to IxDA Interaction08 | Savannah* February 8-10, 2008 in Savannah, GA, USA Register today: http://interaction08.ixda.org/ ________________________________________________________________ Welcome to the Interaction Design Association (IxDA)! To post to this list ....... [EMAIL PROTECTED] Unsubscribe ................ http://www.ixda.org/unsubscribe List Guidelines ............ http://www.ixda.org/guidelines List Help .................. http://www.ixda.org/help
