Michael Gaigg: Über UI/UX Design

14Aug0

Highlights of Week 32/2011

Posted by Michael Gaigg

9Nov1

User-Centered Design (UCD) Methods: Comparison and Overview

Posted by Michael Gaigg

This is the first in a series of blogs describing User-centered Design Methods. My goal is to summarize my experience, insights and findings across multiple literature and compile them into easy and quick to digest pieces for you to consume. I want to encourage you to comment your own experiences and give me feedback on why your company applies certain methods differently or not at all or something else altogether.

I personally don't like the term Usability too much, it's an empty buzz word. It means SOMETHING to everybody but isn't scientific enough to be taken serious. It's often interpreted wrongly and purely misunderstood by most. It's kinda like Psychology, we know it is important to understand fundamental human behavior, their problems and remedies, but I wouldn't pay a dime to go to a Psychologist. But who knows, just as Psychology got its scientific relevance and acknowledgment - partly maybe through the 'invention' of the IQ - hopefully Usability rises up to similar levels (Jeff Sauro offers interesting metrics via SUM (Single Usability Metric).

That's why I like the term User-centered Design. It works wonders with Project Managers and the-like, probably because Design is such an important term in their daily work. And when asked about Usability testing I can conveniently point out that this is only one tool of many in my UCD toolbox. But the really important sales trick is to know which UCD method is best used at what time in the project management cycle.

The following chart compares the most common user-centered design methods, outlines their cost and shows when to use them:

Overview of user-centered design methods

Comparison of User-centerd Design (UCD) Methods
Method Cost Output Sample Size When to Use
Competitive Studies Medium Stat. & Non-Stat. 5 Requirements
Focus Groups High Non-Statistical 6-9 Requirements
Field Studies High Non-Statistical 2-3 Requirements
Heuristic Evaluation Low Statistical 2-3 Design
Paper Prototyping Medium Stat. & Non-Stat. 5 Design
Card Sorting High Statistical 15-20 Design
Participatory Design Low Non-Statistical n/a Design
User Testing Medium Stat. & Non-Stat. 5 Design & Evaluation
Surveys Low Statistical 20+ Requirements & Evaluation
Interviews High Non-Statistical 3-5 Requirements & Evaluation
Server Traffic Log Analysis Low Statistical n/a Evaluation
Search Log Analysis Low Statistical n/a Evaluation

Not long ago, after having completed a full project management cycle (requirements, design, implementation and evaluation) the PM proudly announced to perform a Focus Group with his stakeholders. Showing the ready application, he thought, would surely impress them and lead to valuable feedback for the next milestone. This impulse isn't uncommon but has to be fought before it becomes reality. Does he really want to produce MORE and EXPENSIVE requirements? Because that's the output of Focus Groups. Wouldn't he be better off running 2 iterations of User Testing to reveal usability issues or a Survey to receive input from outside the development environment?

Recommendations

  • Requirements:
    • Competitive Studies
    • Interviews
    • Field Studies
  • Design:
    • Heuristic Evaluation
    • Paper Prototyping
    • User Testing
  • Evaluation:
    • Surveys
    • Server Traffic Log Analysis
    • Search Log Analysis
    • User Testing
  • The Usability effort is NOT proportional to the size of the project. Bigger projects spend less percentage on UCD with same effort. Regardless, as a rule of thumb assign 10% of the projects budget for UCD.
  • Faster iterations of prototype design require less testers

References