I used to teach Excel at an adult vocational college. When I moved into the corporate world, I quickly learned why the University of Hawaii’s research found that well over half of spreadsheets have critical errors. Even the people treated as Excel experts were often clueless.

I’m not saying that spreadsheets should be banned from the workplace, but they definitely need to be very tightly controlled.

Oh, and always, always lock formula cells, even in sheets that never leave your control. :) If possible, make use of Excel’s native data forms, too.