Antonio, I like to add a personal visit so I can determine why assignments might be late, missing, or done incorrectly. Some assignments are routine and very basic, while others require original thought and application. Tests and quizzes are there to assess learning, so sharing advice, suggestions, and conveying interest in the students success help contribute to the students feeling that I care and am there for their benefit. Emails can convey information but lack tone, inflection and emphasis, and sometimes, students respond better to personal interaction with their instructor. Barry Westling