What Do Young Science Students Need to Learn About Variables?

Have the Next Generation Science Standards fulfilled a goal of specifying the objectives of precollege science education in clear and exact enough terms to make them readily implementable? Using students' understanding of the concept of a variable as a case in point, the author suggests that the standards, despite their seeming precision and clarity, leave critical questions not fully answered regarding what K-12 students need to master to be judged knowledgeable regarding scientific practices. This is especially the case given that scientific practices entail not only procedural knowledge but also epistemic understanding, i.e., the purposes and ends toward which practices are conducted. If the teacher does not fully appreciate the epistemic component and lacks deep understanding of procedures, engaging students in related activities is less likely to seem worthwhile to the teacher and in turn to students, leaving teachers tempted to focus attention on content-defined learning, where goals are clearer. (C) 2016 Wiley Periodicals, Inc.