...
Although all our users were eventually able to discover that the study focus combobox could be pressed to display the study focus history , some (Task 8), Users 1 and 3 took a while to discover that it was a combobox which contained the previous study focuses as well, not just the current study focus. This is likely because the only affordance that is provided is a small arrow indicating that it's a combobox - this certainly doesn't pass the squint test. The arrow should be made larger and more apparent; additionally, the label "study focus" above the combobox should be changed to reflect that it can also be used to display the previous study focuses - for example, "current and past study focuses".
...