Posted by: bbannan | February 28, 2011

Formative evaluation and Usability Testing – Jesse

Imagine you’ve been invited to a very special potluck event.  You want to impress and delight everyone in attendance.  You decide to take a risk and try a new recipe.   You could just cook the new dish for the first time right before the potluck, serve it, and hope for the best.  Or, you could first try this dish out on your family to work out the kinks.  You decide to go with the latter approach.

As your family enjoys the new meal you ask for feedback and they report it is great, but a little too salty.  You decide to make some adjustments and then try the dish again, but this time you decide to invite the neighbors over.  Everyone raves about the tasty unique dish, and indicate the salt level is just right.  At this point you feel your dish is ready for prime time at the potluck event next week.

Although this analogy is far from perfect (and pretty corny), it demonstrates the benefit of formative evaluations (ie. periodic prototype validations throughout the design process), namely timely feedback that can be used to improve the product.  So, what are the types of formative evaluations that can be conducted by designers?   We have already discussed needs and task analysis, focus groups, interviews, surveys, and usability testing, all types of formative evaluations.  According to Brown and Green (2006), even rapid prototyping, often considered a process, is a type of formative evaluation since its primary focus is on the iterative steps of create, test, feedback, and adjust.

This week we will discuss in detail the formative evaluation called usability testing.  As you all have read in Kuniavsky (2003), usability tests are essentially focused interviews of the target audience (evaluator).  What makes these interviews unique is the evaluator is asked to interact or try out certain features of the prototype.  This user-centered feedback allows the designers to see the prototype’s functionality from the user’s perspective (ie. Do the design features make sense from the user’s perspective?).  As Kuniavsky suggests, this testing is “probably the fastest and easiest way to tease out show stopping usability problems before a product launches” (2003, p. 259).

Kuniavsky (2003) suggests that usability tests should be done early and often.  So, initially usability testing could be done with paper (watch the first 3 minutes of this paper based usability prototype activity to get the idea, and notice the picture in picture as discussed in Kuniavsky p.286: http://www.youtube.com/watch?v=ppnRQD06ggY), and then continually with a working prototype as it is developed and enhanced in an iterative process.

No matter what combination of formative evaluations you select throughout the design process, it is clear that they key to user-centered design lies in insuring that significant amounts of feedback comes from the end-users.   This feedback should drive changes to the prototype, and in the end, deliver products that make sense to the customer.

References:

Brown, A., & Green, T.D., (2006).  The Essentials of Instructional Design.   Upper Saddle River, NJ: Pearson Education, Inc.

Kuniavsky, M. (2003).  Observing The User Experience.  San Francisco, CA: Morgan Kaufmann.

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