Having weaker students is especially time consuming for faculty for unexpected reasons. No, they don't really take more time in direct instruction, because often the ones that need to show to office hours aren't coming. It's the ancillary issues, such as
- answering more e-mails regarding learning software issues "Prof, I can't get this to upload right"
- spending more time clarifying instructions "I don't understand what we are supposed to do"
- providing an unprecedented level of support for studying
- from learning objectives: "Be able to describe the molecular mechanisms of such and such"
- to question by question instructions "Be able to answer questions 4, 5, 6B and 6C"
- Have thick skin when blamed for student's poor grades in the course
- Have thick skin when faced with pervasive disengagement despite herculean efforts to be student-centered
- Have the wisdom to not let the "it's because our students are weaker" become a self-fulfilling prophesy