CLIFFORD KONOLD AND ALEXANDER POLLATSEK
most basic questions in analyzing data involve looking at group differences to
determine whether some factor has produced a difference in the two groups.
Typically, the most straightforward and compelling way to answer these questions is
to compare averages. We believe that much of statistical reasoning will elude
students until they understand when a comparison of two averages makes sense and,
as a corollary, when such a comparison is misleading. If they do not understand this,
students’ explorations of data (i.e., “data snooping”) will almost certainly lack
direction and meaning.