Prototyping

REVIEW : Why a prototype? Helps with: –Screen layouts and information display –Work flow, task design –Technical issues –Difficult, controversial, critical areas

Low-fidelity (LoFi) Prototypes Quick and cheap to make, easy to change Use a medium which is unlike the final medium, e.g. paper, cardboard Examples sketches of screens, task sequences, etc ‘Post-it’ notes storyboards ‘Wizard-of-Oz’

Surprisingly… In many circumstances, LoFi prototypes work better than HiFi prototypes Why? The goal is to try out lots of ideas fast, early in development (when changes are cheap) –“To get a good idea, get lots of ideas” HiFi prototypes take too long to develop

Surprisingly… Testers focus on superficial issues rather than content Developers resist changes HiFi prototypes can set unrealistic expectations A single bug in a HiFi prototype can halt testing Downside of LoFi prototypes: hard to envision course of an interaction –Storyboards help

Need a “toolkit” for making LoFi prototypes Construction paper Note cards Post-it notes Scissors Glue, tape Lots of paper copies of standard GUI elements: text fields, buttons, check boxes, radio buttons, labels, etc.

For More Information…

Let’s go to the Film First 5 chapters of Nielsen DVD

Storyboards Series of sketches showing how a user might progress through a task using an interface Often used with scenarios, bringing more detail Make it easier to envision the progress of the interaction

Medium fidelity prototypes Now move to the computer (e.g., use Visual Basic) –Simulate some but not all features of the intended system  more engaging for users Purpose –Provide interactive (but limited) scenario for user to try out; gets around limits of LoFi prototypes on testing flow of interaction –May offer a development path to running system

How do you limit functionality? Horizontal prototypes –Entire UI is implemented, but no underlying functionality Vertical prototypes –Include in-depth functionality for a few features –Common design ideas can be tested in depth Scenario-based –Scripts of particular uses of the system; no deviations Wizard of Oz – human simulates the intelligence

High fidelity prototypes Basically complete running system But may not be: –In a suitable language for delivery –Efficient –Robust –Well-coded “Build one to throw away”… a common research methodology

Recall benefits of LoFi Prototypes LoFi prototypes are very quick to develop –Early in the process when changes are cheap Users focus on content instead of superficial issues Developers aren’t yet invested, thus are willing to change Don’t set unrealistic expectations No bugs to halt testing

The Prototyping Spectrum Brainstorm different representations Choose a representation Rough out interface style Task centered walkthrough and redesign Fine tune interface, screen design Heuristic evaluation and redesign Usability testing and redesign Limited field testing Alpha/beta tests LoFi (paper) prototypes Medium Fidelity prototypes HiFi Prototypes / restricted systems Working system Early design Late design

Next Steps Project –Paper Prototypes due next week