Usability Engineering Lifecycle




Introduction

Designing an interface for a new product is exciting but challenging. Because we do not have a previous layout to improve upon, the task of designing a good interface is especially daunting and we were forced to think about usability issues from the start. Instead of creating something and hoping it will just "work", we have decided to systematically build the interface using guidelines, structure, and feedback from various users. Since the final interface should not only provide a gateway of functionality but ultimately enrich the application experience, we as interface designers strive to include the user (a sample of our actual users) in the design process. Therefore, this process will be an evolutionary one in which the initial design assumptions will give way to a solid final interface.

 




Usability Life Cycle

For this project, we are using an abbreviated version of the usability life cycle. Basically, by following each step on the design path, we should be able to come up with a relatively solid interface. The stages in our process are as follows:

 

·         Customer profile - talk with the customer and determine his needs and wants

·         User stories/scenarios - based on the customer interview, develop stories that
will help guide the thought process in the design.

·         Prototype the first design - this is done from the previous two steps

·         Cognitive walkthrough/Evaluation of prototype - does the interface actually
do what we think it will do? Does it meet the customer's needs?

·         Prototype test - customer test drives the first interface and gives feedback

·         Analysis and redesign - based on results from the previous step, identify and
correct problem areas

·         User Test - get a representative group of users to test the prototype

·         Analysis and redesign - fix anything that is broken based on the test. Add
functionality; incrementally build the final interface

·         Evaluation - designers will go through the latest version of the prototype
with the mindset of actual users. Identify any problems or difficulties.

·         Analysis and redesign

·         User Test - test the fully functional application

·         Analysis and final redesign - identify and correct any remaining problems

 




User Testing

We used four users to test the first prototype of the mall manager interface (wizard and main application window). Four users allowed us to see and identify most of the usability problems. The tasks that we presented our test subjects represented the whole range of what a user could do with the interface. For this round of user testing, we used a "paper prototype" instead of allowing the users to play with the prototype on the computer. We chose to do this because we thought the users might get confused with the limited functionality of the current version of the application. We felt that a paper prototype would allow them to see and tell us what they would do in certain situations. The screen shots that we used can be found here . Before the test began, we had each user complete a questionnaire of basic information. This information will help us when we analyze the results of the test. They finished the questionnaire by evaluating their experience in the test.

Our test results are here.