Perhaps the academic community demands too much in the way of perfection, or at least our perception of perfection, in middle-school texts. A case in point is John Hubisz’s criticism of a text for defining “acceleration” as a “change in velocity” rather than as the rate of change in velocity (see Physics Today, Physics Today 0031-9228 56 5 2003 50 https://doi.org/10.1063/1.1583534 May 2003, page 50 ). I think we are splitting hairs when we criticize so trivial a thing. In a college text, more careful attention to meaning may be needed, but in a ninth-grade physical sciences book, it is perfectly appropriate to define “acceleration” in the terms that the seemingly offending textbook did. The change in velocity is understood to occur over time, as dictated by logic. If one applies a rate of change in velocity as the definition to be learned by the middle-school or beginning high-school student, the concept then becomes too abstract for the typical 13- or 14-year-old.
We must acknowledge the tremendous differences in cognitive maturity that exist between middle-school and beginning high-school students and their older counterparts. What may seem oversimplified for the more mature student is often very appropriate for the younger one. Let’s keep that in mind and realize that writers have to consider the level of understanding of the reader who uses the text.
