I conducted five rounds of "guerrilla usability testing" to find the best design for the margin and options accounts view page. This was a difficult page to design because the margin eligibility rules are complicated (only one account per ownership type can have margin), and a traditional presentation of accounts would confuse users who did not understand the rules. Across all five rounds of testing I asked users to complete simple tasks like "Can you tell me which accounts have margin enabled?" and "How would you get margin on this account?"
The earliest designs tried to show the margin rules in the user interface with forcing functions like dropdowns and radio buttons. This made sense to a room of designers, but participants in usability tests found it confusing. Next I tried a design similar to the other view pages my team members were building, but these overly simple pages combined too much information. The final design created more columns and used longer calls to action than other "standard" designs being created in my group, but made the information users needed explicitly clear and easy to understand. When I asked users questions like "Can you tell me which accounts have margin enabled" and "How would you get margin on this account," participants found the tasks so easy that they wondered if it was a trick question -- a great change from the earliest designs when users couldn't complete the tasks! To deviate from the standard I had to prove that the standard design was less usable than a new design. One non-standard design was the call to action on accounts ineligible for margin. Rather than labeling the link "disabled" or "ineligible" and explaining why somewhere else on the page (which discourages interaction), I labeled the action as "How to enable margin on this account," which brings up a layover that explains the margin rules and how they affect this account.
I also had the opportunity to show my development team in Bangalore, India how I conduct usability testing so they could learn the value of UX. I showed my team my current prototype and asked them how they thought people would interact with it. We then brought in engineers from other teams and had them complete a few tasks. They got to see that we all predicted people would interact with it one way, but users interacted in other ways and questioned things we thought were simple. This helped them see that UX design is an iterative process, and sometimes we have to throw out the current design and find a better one.