1. As George Cobb (1993) remarked, “If one could superimpose maps of the routes taken byall elementary books, the resulting picture would look much like a time-lapse nightphotograph of car taillights all moving along the same busy highway” (p. 53).
2. David Krantz (personal communication, December 13, 2001) shared with us his response to the question, “Do we really need the mean in descriptive stats?” which had appeared on a data analysis listserv. “I’m not very clear on what is meant by ‘descriptive statistics.” To be honest, I don’t think there is any such thing, except as a textbook heading to refer to the things that are introduced prior to consideration of sampling distributions. Any description must have a purpose if it is to be useful—it is supposed to convey something real. The line between ‘mere description’ and suggesting some sort of inference is very fuzzy.”
3. Many use the term central tendency as a synonym for average or center. When referring to central tendency in this article, we have in mind the particular definition specified here.