Interaction Design Association - Homepage. Insights and inspiration for the user experience community. 10 Must-Follow Usability Experts on Twitter. Nick Gould is CEO of usability and user experience design firm, Catalyst Group. He is @nickgould on Twitter. The popularity of the “#fail” meme on Twitter is proof positive that the tool is great for pointing out when things are wrong. TandemSeven: User Experience Experts. UPA - The Usability Professionals' Association.