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As we saw from how User 2 didn't initially press the "Make Study study focus" button on task 3, he apparently didn't understand what "study focus" meant (namely, that the study focus must appear in fetched sentences). We could perhaps have replaced the term "study focus" in our interface with a term which better described what it meant for a word to be the study focus, for example, "word which must appear in fetched sentences".
Study focus history functionality has poor information scent
Although all our users were eventually able to discover that the study focus combobox could be pressed to display the study focus history, some took a while to discover that it was a combobox. 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".
Ctrl-F is inconsistent with usual browser search functionality
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