The Detailed Comparison of Content lists in detail SFAA/Benchmarks material, when any could be found, for every fundamental idea or ability in NSES, and NSES material, when any could be found, for every benchmark in Benchmarks. Based on that compendium, the observations below compare the NSES content standards with SFAA/Benchmarks in terms of congruence, level of difficulty, and treatment.

With regard to congruence, an effort was made to characterize the overlap between the two "circles of content" (see Figure 1). It turned out to be easier to express this in terms of what content was outside the overlap. In table 5, we list the topics noted in Benchmarks chapters 1 (The Nature of Science), 3 (The Nature of Technology), 4 (The Physical Setting), 5 (The Living Environment), 6 (The Human Organism), 10 (Historical Perspectives), 11 (Common Themes), and 12 (Habits of Mind) that are not included specifically in any NSES content standards. In table 6, we list the topics noted in all NSES content standards that are not included specifically in any chapter in Benchmarks.

Two important conclusions emerge from this analysis:

Given the vast intellectual territory at stake, what is most impressive is the great similarity between the content of the two versions, not their differences.

Both visions of what is essential for everyone to know exclude a host of topics--Ohm's law, series and parallel circuits, geometric optics, phyla of plants and animals, cloud types, Punnett squares, ideal gas laws, plant physiology, specific heat, simple machines, balancing chemical reactions, and many others--that congest the traditional science curriculum. Any one of these could nevertheless be studied, by all students as a context in which to learn many other things that are specified, or by some students with special interest in science. (For example, balancing chemical equations might be seen as a good context for learning conservation of matter.) But both documents hold that not all students would be held accountable for the cloud types, etc. themselves.

Regarding level of difficulty, the analysis looked for instances in which 1) NSES fundamental concepts appear to be more intellectually demanding for high-school graduates than the corresponding ones in Benchmarks, or vice-versa; or 2) NSES grade-range placement of given content differs from that of Benchmarks.

Both visions of literacy stop well short of the traditional allegiance to details-and-vocabulary-at-the-expense-of understanding, often at almost precisely the same level of detail. For example, in describing the periodic properties of the elements, both NSES and Benchmarks restrict themselves to the idea that there are periodic properties, with no description of the periodic table. Where there is a difference in difficulty, of which there are relatively few, they are usually in the direction of NSES standards being more advanced. Table 7 presents a list of the ideas that NSES takes further than Benchmarks. Some of those that should be especially noted are the following:

Benchmarks asks that students know that like charges repel one another while opposite charges attract, whereas NSES asks that they also know the strength of the force is proportional to the charges and inversely proportional to the square of their separation.

Benchmarks asks that students know that discrete energy changes in atoms is accompanied by emission or absorption of light of discrete wavelengths, whereas NSES asks that they also know that the wavelength of the emitted light is inversely proportional to the energy change.

Benchmarks asks that students know only that the information passed from parents to offspring is coded in DNA molecules, whereas NSES asks that they know DNA is a large polymer formed from subunits of four kinds (A, G, C, and T).

Benchmarks asks that students know only that animals get energy from oxidizing their food, whereas NSES asks that they know cells store the released energy temporarily in phosphate bonds of a small high-energy compound called ATP.

NSES places some topics in different grade ranges than Benchmarks does. In most cases, Benchmarks and NSES place ideas in the same grade ranges. When differences occur, it seems that they are as often in one direction as the other, i.e., Benchmarks seem to include ideas earlier than NSES just as frequently as NSES includes ideas earlier than Benchmarks. (For instance, among the benchmarks matched to NSES's 5-8 fundamental concepts there are just as many outsiders from the 3-5 Benchmarks range as there are from the 9-12 Benchmarks range.)

NSES includes plate tectonics, evolution, and natural selection earlier than Benchmarks does. Benchmarks includes atoms and molecules and links the flow of matter in ecosystems to the study of atoms earlier than NSES. We believe that the research supports the placement of natural selection and evolution in later grades (Brumby, 1979; Bishop & Anderson, 1990). Research related to students' understanding of atoms and molecules suggests that carefully designed instruction can help middle-school students develop correct ideas about atoms and molecules, although several deficiencies in students' understanding remain despite these approaches (Lee, Eichinger, Anderson, Berkheimer, & Blakeslee, 1993). Hence, the delay is reasonable. There is very little research related to students' understanding of plate tectonics.

The main differences of treatment include the following:

1) Benchmarks often includes benchmarks that are precursors or prerequisites for understanding concepts that will come later. Most of these are thought to be worth knowing in their own right, but some are temporary, contributory understandings. Relative to Benchmarks, NSES content standards include fewer items that might be thought of in this way. This accounts, in large measure, for the fact that with regard to the territory that they both include, there are more benchmarks than fundamental concepts and abilities.

2) NSES sometimes repeats essentially the same standard at successive grade levels. This is particularly noticeable in the sections on abilities of technological design and abilities related to scientific inquiry.

3) Finally, while it is not usually the case in NSES, some of its fundamental concepts are essentially definitions--atom, compound, populations, ecosystem, probability, prediction, and evidence are examples. Benchmarks are rarely definitions.

Figure 1
Common Ground: Project 2061 and NSES

Table 5
Ideas/topics in SFAA/Benchmarks that are not included in NSES 

Forms that bias can take and precautions to minimize the bias (p. 12)

Historical exclusion of women and minorities (p. 17)

Rationale for why one would take an observational rather than an experimental approach (p. 13)

Special care in using animals in scientific research (p. 17)

Feedback and control in technological systems (pp. 51-52)

Technological failure and ways of reducing it (pp. 51-52)

Issues of maintenance in technology (p. 52)

Distances between earth and stars (p. 64)

Characteristics of stars (p. 65)

Light from distant stars shows universality of elements, principles (p. 65)

Unique ability of planet earth to support life (p. 70)

Existence of yet smaller components of protons, neutrons, and electrons (p. 80)

Poor heat conductors can be used to reduce heat loss (p. 84)

All motion is relative to frame of reference chosen (p.91)

The effect of motion on observed wavelength and how the expanding universe is inferred from that (p. 92)

Use of DNA sequences in biological classifications (pp. 105, 130)

Biological variation increases likelihood of some surviving individuals (p. 105)

New gene combinations can be helpful, harmful, or neutral (p. 108)

Increased mutation rate (and cancer risk) from chemicals and radiation (pp. 109,114)

Cell's watery composition accounts for many of its properties (p. 112) Proteins as long folded chains of smaller molecular units (p. 114)

Most cells function best within a narrow range of temperature and acidity (p. 114)

Cyclic fluctuations and equilibrium in ecosystems (p. 117)

Explanation of what fossil fuels are and the consequence of carbon-dioxide release of using them (p. 121)

Selective breeding (as application of science in agriculture and as a model for natural selection) (pp. 124,186) Bush-like nature of evolution (p. 125)

Aging (NSES has other aspects of human life cycle) (p. 133)

HUMAN IDENTITY -- whole section (pp. 127-130)

Coordination by chemical signals (hormones) (pp. 137, 138)

LEARNING -- whole section (NSES section The Behavior of Organisms does not include this) (pp. 139- 142)

MENTAL HEALTH -- whole section (NSES section The Behavior of Organisms does not include this) (pp. 147-149)

Specific principles of reasoning (pp. 231-234)

"Emergent" properties of complex systems (p. 266)

Unpredictable effects of changing some part of the system (p. 266)

Symmetry as an aspect of constancy (pp. 273, 274)

Characteristics of cycles (p. 274)

Maintaining equilibrium (in general, though NSES has homeostasis) (p. 275)

Unpredictability of some systems (p. 275) Expressing very large or very small magnitudes with powers of

ten (p. 279)

Table 6
Ideas/topics in NSES that are not included in SFAA/Benchmarks

Types and levels of organization, and hierarchies as common themes (p. 117)

Explicitly, importance of measurement in science (p. 118)

Different systems of measurement (p. 118)

Separation of mixtures of substances by their properties (p. 154)

Chemical reactions are oxidation/reduction (exchange of electrons) or acid/base (exchange of hydrogen ions), radicals as reactive units (p. 179)

Identification of protein catalysts as "enzymes" (p. 179)

"Complementarity of structure and function" as a theme in biology (p. 119, 156)

Identification of DNA molecule as "chromosome", human chromosome number (p. 185)

Behavior patterns "ensure reproductive success" and "must be flexible enough to deal with uncertainty and change" (p. 187)

An inherited trait can be determined by one or many genes, and a single gene can influence more than one trait (p. 157)

Metallic core of earth (p. 159)

Atmosphere includes nitrogen (p. 160)

Clouds affect weather and climate (p. 160)

Radioactivity and gravitational energy of formation as sources of earth's hot interior (p. 189)

Because water is a solvent, it transports dissolved substances with it wherever it goes (p. 160)

General notion of a "reservoir" in systems (p. 189)

Safety and injury prevention (pp. 168, 197)

Sex transmits diseases (pp. 168, 197)

Severity of disease symptoms (p. 197)

Variety of factors influencing decisions about health practices (p. 197)

Mood and behavior can be modified by substances (p. 197)

Natural Hazards (pp. 168, 198, 199)

Pursuing science as career or hobby can be fascinating and intellectually rewarding (p. 200)

"Science distinguishes itself from other ways of knowing...through the use of empirical standards, logical arguments, and skepticism..." (p. 201)

Additional episodes in the history of science (p. 204)

Molecular biology

Information and communication

Quantum theory

Galactic universe

Medical and health technology

Table 7
Ideas that NSES takes further than SFAA/Benchmarks

Assumption of order in the universe establishes the basis for cause-effect relationships and predictability (p. 116)

Different terms such as hypothesis, model, law, theory and paradigm are used to describe various types of scientific explanations (p. 117)

Steady state, balance, and homeostasis describe equilibrium states (p. 119)

The periodic table is a consequence of the repeating pattern of outermost electrons and their permitted energies (p. 179)

Gravitational attraction is an inverse-square law (p. 180)

The strength of the electric force is proportional to the charges and inversely proportional to the square of the distance between them (p. 180)

The energy of electromagnetic waves is delivered in packets whose magnitude is inversely proportional to the wavelength (p. 180)

All energy can be considered as kinetic energy, potential energy, or energy contained by a field (p. 180)

The subunits in the DNA polymer are of four kinds: A, G, C, and T (p. 185)

Strong (covalent) bonds are formed between atoms of organic molecules (p. 186)

Cells store the released energy temporarily in phosphate bonds of a small high-energy compound called ATP (p. 186)

Exponential growth of populations (p. 198)

Return to TOC