Teacher question: There is much interest in many states to reduce the number of student contact days.  The typical 180 student contact days are being questioned and often replaced with fewer instructional days that are often only a few minutes longer.  Is there any research on four-day weeks versus the typical 180 school day calendar? Shanahan responds: Amount of instruction is an important variable in academic achievement. Usually, if we increase the amount of teaching by a reasonable amount, we tend to see increases in learning. From eyeballing the research studies, I&...