As California proceeds with implementation of the Next Generation Science Standards (NGSS), a major point of contention is likely to be how to sequence science content in the middle-school grades.
Currently in California, the various middle school science topics are grouped together within grade levels roughly by discipline: earth science in 6th grade, life science in 7th grade, and physical science in 8th grade. The newly-adopted NGSS only describe what topics are to be covered in “middle school”, leaving individual states to decide how to sequence content in grades 6-8.
The traditional, discipline-based approach is common across the country and has served California well under our previous science standards. However, the state Board of Education has also approved an alternative, “integrated” approach which would expose students to a combination of earth, life, and physical sciences at each grade level. Under guidelines adopted in November, districts will be able to choose between implementing a traditional or integrated model in their schools.
The Board of Education is to be commended for not imposing the integrated model – favored by many officials but opposed by many teachers – on the state’s schools. Such an integrated approach is intuitively appealing, but does not stand up to scrutiny. It would therefore be a mistake for California’s districts to abandon the advantages of the traditional, discipline-based content sequence.
The primary rationale for integrating the sciences in middle school is that doing so will allow teachers to highlight – and therefore help students to understand – how even seemingly-unrelated scientific content can be unified by the “crosscutting concepts” and science “practices” emphasized by the NGSS. So, for example, under the proposed integrated 7th grade standards, students would learn about both ecosystems and chemical reactions because both topics incorporate broad, scientific concepts like “cause and effect” and energy flows.
This logic ultimately fails. While it is true that even disparate-seeming scientific content can be unified by overarching scientific concepts, this would be the case for any arrangement of topics. The beauty of such crosscutting concepts in science is precisely that they are applicable across content areas. Highlighting and illustrating general, unifying principles in the science classroom is a worthwhile educational endeavor. There is no need, however, to arrange science content specifically to illuminate abstract science concepts or universal science practices; any arrangement will do.
Additionally, while the abstract interrelatedness of various scientific disciplines may seem obvious to most science educators, recognizing those relationships requires a relatively sophisticated understanding of each content area that many middle school students will lack. Ideally children would acquire such deep understandings of individual disciplines. The NGSS, however, discourage factual depth in individual content areas.
Moreover, scattering closely-related content across the different grade levels will likely make in-depth exploration of a discipline more difficult by requiring additional review in the later grades. For example, the approved integrated content arrangement introduces much of natural selection in 8th grade. A deep understanding of natural selection requires, among other things, considerable knowledge about heredity, but under the integrated model crucial information about heredity is introduced in 6th grade. This means that it may be two years or more since students learning about natural selection as 8th graders have thought about important aspects of heredity. This, in turn, makes it likely either that students will develop less-sophisticated understandings of natural selection, or that teachers will be required to dedicate substantial time to reviewing content from previous years.
While there is little reason to prefer an integrated approach to middle school science, there are many advantages to the traditional, discipline-based approach.
First, many teachers have strong preferences for teaching particular scientific content. I prefer teaching physical science and life science, for example, and actively dislike teaching most earth science. This preference is not entirely arbitrary: I know considerably more about the life and physical sciences than I do about the earth sciences, and have much more experience about how best to teach them. Requiring teachers to muddle through content they dislike or about which they are less knowledgeable is likely to be both unpleasant for them and less productive for students.
Second, it is important to remember that the “traditional”, “discipline-based” arrangement is already integrated. What we refer to as “8th grade physical science”, for instance, includes chemistry, physics, and astronomy. Those are three distinct scientific fields unified only loosely under the “physical science” label. At the same time, these physical science topics are related closely enough to allow typical middle school students to draw meaningful connections between them.
The previous 8th grade standards, like their sixth- and seventh-grade counterparts, also include more ambitious integration where appropriate. When 8th graders learn about chemistry, for instance, they also learn about the “chemistry of living systems,” which aligns neatly with other chemistry standards while allowing students to make connections to the life sciences.
In other words, the difference between the traditional and integrated models is not whether they are integrated per se, but how distantly related the integrated topics are. More traditional models can be usefully integrated without presupposing a level of expertise middle school students are unlikely to possess.
Given the virtues of the traditional, discipline-based approach to organizing science content in middle school, it is unlikely that a more heavily-integrated approach would be an improvement.
Paul Bruno is a middle school science teacher who worked in Oakland before relocating to Southern California. He also blogs at This Week in Education.