Introducing Evaluation: why, what, when, where Text p Text p 317 – 323;

Bruce Tognazzini tells you why you need to evaluate “Iterative design, with its repeating cycle of design and testing, is the only validated methodology in existence that will consistently produce successful results. If you don’t have user-testing as an integral part of your design process you are going to throw buckets of money down the drain.” See AskTog.com for topical discussions about design and evaluation.

Why, what, where & when Where: –in natural and –laboratory settings. When: –throughout design; –finished products can be evaluated to collect information to inform new products. Iterative design & evaluation is a continuous process that examines: Why: to check that users can use the product and that they like it. What: –a conceptual model, –early prototypes of a new system and later, –more complete prototypes.

Why evaluate? Designers get feedback about their eraly design ideas Major problems are fixed b fore the product goes on sale Designers focus on real problems rather than debating what each other likes or dislikes about the product

Why evaluate You will never second-guess how people use your designs We all get emotionally attached to our designs and need perspective Yes, your baby may be ugly

What to evaluate? Usability Emotional qualities Engaging qualities Motivating qualities

Where to evaluate Depending what you are evaluating will determine location Examples – how different users use a mobile phone will require a naturalistic setting –Sequence of links on a website can be done in a controlled lab setting

When to evaluate Throughout design From the first descriptions, sketches etc. of users needs through to the final product Design proceeds through iterative cycles of ‘design-test-redesign’ Evaluation is a key ingredient for a successful design.

When to evaluate Depends on the product Summative evaluation occurs to assess the success of a FINISHED product Formative evaluation is done ruing the design process to check that the product continues to meet users needs Formative evaluation cover abroad span of the design from early development sketches etc, to tweaking an almost finished design

The language of evaluation Analytical evaluation Controlled experiment Field study Formative evaluation Heuristic evaluation Predictive evaluation Summative evaluation Usability laboratory User studies Usability studies Usability testing User testing activity Evaluation has a set of terms with which you will need to become familiar. Use your text to find the definitions of the main ones listed here