I decided that the best way to assess the need for expanded

先省略方括号中的从句：
I decided that the best way [to assess the need for expanded hours] was to talk to the people [who were still in the student center at closing time]
大意是：
我认为,与教学楼（直译为“学生中心”）关门时还在那儿的人交谈是估量（人们）对扩充时间的需求的最好方式.