Reviewing a general-science series for high schools

Science Probe I
1997. 552 pages. ISBN: 0-538-66900-4.

Science Probe II
1997. 543 pages. ISBN: 0-538-66901-2.

South-Western Educational Publishing, 5101 Madison Road,
Cincinnati, Ohio 45227. (South-Western is a division
of International Thomson Publishing Inc.)

Good Textbooks That May Be
Useful in Grades 7, 8 and 9

Lawrence S. Lerner

The Science Probe books offer what is commonly called integrated science, though South-Western calls it "coordinated" science. South-Western's promotional brochure for these books says:

We're leading the way into science reform with this two-year coordinated science curriculum. The future in science education is here now . . . only from South-Western Science. . . .

Coordinated science means "every science, every year" . . . a refreshing way to teach and a more meaningful way to learn. In this approach, the four disciplines -- Biology, Chemistry, Physics and Earth/Space Science -- are connected within the units. Science Probe has captured this approach in a two-year curriculum primarily for 9th and 10th grade students. . . . Science Probe I and II provide for a two-year, high school science requirement.

Traditionally, science has been taught in American middle schools and high schools as a sequence of discrete subjects -- life science, earth-and-space science, and physical science (in grades 7 through 9), and then biology, chemistry, and physics (in grades 10 through 12). During recent years, much has been said and written about the purported advantages of integrating life science, earth-and-space science, and physical science into a single subject, which would be taught over several years. This approach is no novelty. It has been used in most European countries for a long time.

Now that nearly all the states of the Union are composing subject-matter standards, the choice between the traditional system and the integrated system has become urgent: Which one shall the states incorporate into their standards for science education? Each approach has its advocates, but as a matter of hard fact, nearly all the states that have adopted standards have embraced the traditional system. To the best of my knowledge, the only exception is West Virginia -- and West Virginia's standards are so muddled and so poorly written that they cannot be taken as a fair model of the integrated system. (See my report State Science Standards, in which I have evaluated the standards developed by 36 states. The report -- available on the Internet at http://www.edexcellence.net -- was published in March by the Thomas B. Fordham Foundation.)

The committee that was charged with developing California's science standards considered the integrated approach, but that effort was nipped in the bud by one of the committee's members, the Nobel laureate Glenn T. Seaborg. Seaborg (who had the ear of the governor) promised that if the integrated approach were accepted, he would write a dissenting report and would surely prevail. The committee then adopted a "focus" approach, in which the traditional sequence was preserved but some links among the various sciences were mooted at each grade level.

Aside from tradition, there is another factor that weighs against the integrated approach. Many teachers are simply not prepared to teach all the sciences -- especially the physical sciences -- proficiently.

Hence it is difficult to credit South-Western's claim that integrated science represents the "future in science education."

Now, what about South-Western's attempt to position the Science Probe textbooks as high-school books? This attempt raises two issues. First: If high-school students were to study integrated science in both grade 9 and grade 10, they would not be able to begin the biology-chemistry-and-physics sequence until they reached grade 11 -- and for college-bound, scientifically inclined students, this would create real difficulties. Second: The Science Probe books seem more suitable for middle-school students than for high-school students. My overall appraisal of these books is that they are good middle-school texts -- better, in terms of both presentation and scientific accuracy, than almost all the middle-school books that I have reviewed heretofore. Integrated-science courses based on the Science Probe books can serve as useful precursors to, but not as substitutes for, the high-school science courses that students have traditionally taken in grades 10 through 12. In the analysis that follows, therefore, I shall consider the Science Probe books for use in grades 7 and 8 or in grades 8 and 9.

There is much good in these books, but there are significant faults as well. Let me start with the good:

Both books offer text written in clear, literate English by writers who understand their subject matter. The sidebars make sense, for the most part, and usually are relevant to the text that they accompany. Many of the experiments and other projects presented in the "Activity" boxes can serve as fruitful learning experiences; relatively few of the "Activity" items are mere busy-work or contain unanswerable questions. And many of the problems, though not all, seem useful. Here is one example, typical of the best:

A student combed his hair and then brought the comb near some sawdust. At first, the sawdust was attracted to the comb. Then, after touching the comb, it was repelled. Explain these observations. [volume II, page 49]

A student who can answer this question has learned quite a lot about electrostatics.

In almost all cases, the writers show respect for numbers -- that is, the values given for physical quantities are almost always realistic.

The pedagogy is generally appropriate for students in grades 7, 8 or 9, but I noticed some pedagogic inconsistency when I compared the two volumes. The chemistry and geology presented in volume II are slightly but significantly more advanced than the chemistry and geology in volume I, but the biology in the second volume is no more sophisticated than the biology in the first.

Each volume has a useful glossary -- a rarity in science books at this level.

Some chapters are outstanding in their clarity and usefulness. Examples from volume I include chapter 10 ("Fitness and Health: A Way of Life") and chapter 14 ("The Stars"). The latter has a fine, semiquantitative exposition of the use of triangulation in measuring stellar distances. Another exceptional passage appears in chapter 15 ("Exploring the Universe"): Here the writers use a good analogy -- based on comparisons between geographical distances and the thickness of a sheet of paper -- to convey the relative magnitudes of various astronomical distances.

The writers' treatment of energy in volume I is not rigorous, but it is good. Read, for example, these paragraphs from the "Review" at the end of chapter 18:

• There are many forms of energy: sound energy, light energy, mechanical energy, gravitational energy, magnetic energy, thermal energy, chemical energy, nuclear energy, electrical energy, and elastic energy.

• There are two classes of energy: potential energy and kinetic energy.

Would that all textbooks did as well in making the distinction between forms of energy and classes of energy -- a distinction that confuses so many students unnecessarily!

Turning to volume II, I find exceptional work in chapter 3 ("Static and Current Electricity"), chapter 5 ("Using Electricity in Your Home"), chapter 12 ("Geological Time") and chapter 13 ("Earthquakes and the Earth's Interior"). Chapter 5 explains many things that everyone should know but almost no one does. (How can you get both 120 volts and 240 volts from the same three-wire line? How does a ground-fault circuit-breaker work? When you plug in a lamp, why should the outer shell of the socket be connected to the neutral wire?) Chapter 12 has a remarkably comprehensive survey of geological dating methods, and it really conveys the difficult concept of geological time. Chapter 13 considers both practical and theoretical aspects of earthquake waves, and the writers clearly distinguish S waves from P waves. They also come within an ace of explaining how we know that Earth's inner core is solid and its outer core is liquid, but they don't quite get there. This is a pity, because two more paragraphs would have done the trick.

Chapter 16 of volume II is a straightforward and good exposition of reproduction in eukaryotes, including humans, and the writers tell explicitly that "During intercourse [in humans], . . . semen is delivered through the urethra from the penis into the vagina." Their material about contraception is explicit, too, but it has been relegated to an exercise at the end of the chapter:

There are several methods available for preventing pregnancy, that is, methods of birth control. Select one of the methods listed below and do research to determine (a) what is involved in using the method, (b) why it works, and (c) its effectiveness. . . . Present your findings to the class in the form of a poster or a pamphlet, or in some other way. Some commonly used methods of birth control are contraceptive pills, condoms, spermicides, intrauterine devices (IUDs), the rhythm method, and diaphragms.

Volume II also has information about sexually transmitted diseases, but it appears in chapter 15, "The Cell," and it thus precedes the material about sex. The writers offer this advice:

There is much less risk of getting an STD if proper precautions are taken. Here are some ways to protect yourself:

• Abstain from sexual activity. That is the only absolutely safe way.

• If you are sexually active, a condom is always necessary. Since some STDs show no symptoms, you have no way of knowing whether or not your partner is infected. . . .

• Do not allow semen to enter the vagina or anus.

• Drug users are at special risk and must never share a needle or syringe, . . . .

• Remember that drugs and alcohol make people less cautious so that they may not take the necessary precautions.

All this is excellent advice indeed, but I hope that students have already seen it. It should be presented to students in, say, the 6th grade, before any significant number of them have started to experiment with sexual activity or drugs.

• Though the introductory material about energy is good, there is almost no treatment of kinematics or dynamics. Newton's laws of motion are never mentioned.

• There is not enough quantitative discussion, and the mathematics in these books seldom goes beyond simple arithmetic. An exception is the treatment of Ohm's law, in chapter 3 of volume II, where the student must apply some very simple equations.

• There is no information whatsoever about organic evolution, in either volume. Of all the defects which the Science Probe books display, this is the most serious -- and for most teachers, it will be sufficient reason to drop the Science Probe books from consideration. This exclusion of organic evolution is amazing, given that the books offer excellent discussions of cosmological and geological times scales, including the use of index fossils in geological dating. I see a curious and ironic parallel between the exclusion of evolution, the central organizing principle of the life sciences, and the exclusion of Newton's laws of motion, which constitute the central organizing principle of the physical sciences.

• The writers sometimes adopt quirky or misleading nomenclature, for no evident reason. In their chapters about chemistry, for example, they never use the familiar, easy-to-pronounce word valence. Instead they invent the neologism "combining capacity." Similarly, they shun the word radical in favor of the phrase "groups of atoms." They incorrectly assert that "orbit" and "shell" are synonymous (in describing electron configurations in atoms), and they thus deprive themselves of the ability to give any correct explanation of atomic structure or of spectral lines. This difficulty is compounded because they fail to mention that each orbital has a distinct energy level.

• The references to the history of science are very weak, with numerous errors and misinterpretations. For example, a cartoon in volume I shows Copernicus informing his colleagues that "The sun is the center of the universe" -- and the caption says: "When Copernicus published his theory in 1543, other scientists had to change the way they thought about the universe." Of course, this is a far cry from what really happened. The crucial choice between geocentricity and heliocentricity wasn't made until a half-century after Copernicus's death, and then it depended on information that Copernicus didn't have. That information was provided by Galileo and by Kepler.

• When converting the original Canadian books into versions for sale in the United States, the writers and editors were not as careful as they might have been. The presence of both Canadian and American spellings (e.g., meter and metre) is a bit annoying, especially when they are mixed in the same sentence. A cartoon contains a scribbled note saying "Moved to Flin Flon," but most American students have never heard of that little Manitoba town with the funny name. And one must chuckle when one reads that Newfoundland is on the "southeast Atlantic coast" (volume I, page 461).

• In volume I, chapter 18 ("Energy Transformations and Alternative Energy Sources") is seriously marred by the writers' trivialization of nuclear power. The entire subject of nuclear energy has been relegated to an "Extension" note on page 407, which suggests that the student may want to prepare a poster about nuclear fission, nuclear fusion, fuel cells, heat pumps, piezoelectricity or "generators that use wave energy."

• A great deal of space is wasted on efforts to tell the student about "process skills" and "mind maps" -- pedagogical concepts that are best left to the teacher.

Now let me list some particular errors that I have noticed, mostly in volume I.

• Volume I, page 10: The writers imagine an apple whose dimensions and weight are such that its specific gravity is about 0.36. Float an apple in water, and see for yourself how much of it is submerged. I promise you that the answer will be much more than one-third!

• Volume I, page 12: Light pipes do not operate "through the imaginative use of prisms," and I doubt that the light pipe was invented by Lorne Whitehead or any other lone individual.

• Volume I, page 29: A student who is just beginning to learn chemistry isn't equipped to "find out" and understand the chemical reactions involved in using baking powder.

• Volume I, page 32: Hair stylists do not need, and do not usually acquire, extensive training in chemistry.

• Volume I, page 33: The discussion of the accuracy of chemical balances is incorrect.

• Volume I, page 40: Here the student is supposed to tell whether paint, when it "dries," undergoes a physical change or a chemical change. In fact, it undergoes both.

• Volume I, page 44: The section about "The Origin of Symbols for the Elements" offers false "history," both explicit and implied. For example, the ancient Romans knew iron and had a name for it, ferrum, but this doesn't mean that iron occurs in nature "in almost pure form." (In nature, iron occurs only in compounds.) The Latin carbo denoted charcoal or burnt wood, not the element carbon. The Latin alumen was the Romans' name for alum, not for the element aluminum. And even though the chemical symbol for antimony, Sb, is derived from the Latin stibium, antimony itself was not identified until the Middle Ages. (Neither elemental aluminum nor elemental antimony was known in classical times.)

• Volume I, page 52: In a table that shows some chemical compounds and their practical applications, the only formula given for iron oxide is Fe₂O₃; the writers equate this compound with rust, and they say that it is useless. In fact, however, Fe₂O₃ is a valuable component of iron ores, and refined oxides of iron have many applications. Black iron oxide, Fe₃O₄, is used in the manufacture of magnetic inks and magnetic tape, for example. Other iron oxides appear in paints and polishing compounds.

• Volume I, page 100: The quantity of calcium in the body of "a typical adult" is not just "several grams." It actually is more than a kilogram. (On page 111 the writers correctly state that "About 2 percent of your body's total mass is made up of calcium, most of it contained in your bones and teeth.")

• Volume I, page 112: It is not true that persons who suffer from lactose intolerance "cannot eat any dairy products." Such persons find yogurts or fermented cheeses to be quite tolerable. Lactose is converted to lactic acid during the fermentation, and virtually no lactose remains in the fermented product.

• Volume I, page 112: It is not correct that iodine "Controls the thyroid gland," though iodine does appear in thyroid hormones.

• Volume I, page 113: "These foods are good sources of iron," says the caption beside a photograph. The photograph doesn't show the best source of all -- red meat -- but it does show spinach. Spinach is not particularly useful in this context. Its leaves contain a lot of oxalate, and oxalate inhibits the absorption of iron.

• Volume I, page 114: The list of foods that provide vitamin C doesn't mention any animal products. Yet it has been 80 years since Vilhjalmur Stefansson astounded nutritionists by subsisting for a full year on nothing but meat and meat products -- just as the Inuit had done since prehistoric times.

• Volume I, page 115: "Vitamin C and the B vitamins are water-soluble vitamins because they dissolve in water." Do we really want to divulge this arcane knowledge to the young and innocent?

• Volume I, page 123: "Some types of grain, such as wheat, cannot be eaten until they are ground." What about boiling? People eat boiled wheat, in various forms, all over the world.

• Volume I, pages 138 and 139: In covering the physiology of the stomach, the writers fail to point out that the stomach is an absorption site. Certain nutrients pass through the stomach wall and into the bloodstream.

• Volume I, pages 145 and 146: Here the writers attribute gastric ulcers entirely to "hydrochloric acid and pepsin produced by the stomach." They fail to mention the crucial role of Helicobacter, which has been known for a decade or so.

• Volume I, page 182: It makes no sense to ask, "Why is it important that the muscles of your heart have the ability to work without stopping to rest?" Every heartbeat includes a period of rest.

• Volume I, page 274: It is not correct that Jupiter's atmosphere has high winds because Jupiter "is rotating very quickly." The claim that a planet's rotation produces winds was advanced four centuries ago by some of Galileo's opponents, who were attempting to discredit his assertion that Earth rotates -- but the claim is as wrong now as it was then. See my review of the Addison-Wesley book Exploring Matter and Energy in TTL, November-December 1995.

• Volume I, page 295: Wrong. The latitude-dependent variation in the Sun's rate of rotation is not analogous to the transverse variation in a river's rate of flow.

• Volume I, page 354: Yes, Miller and Urey (in 1953) posited that the Earth's primitive atmosphere comprised hydrogen, methane, ammonia and water. But students need to know that the prevailing view among today's scientists is that the primitive atmosphere consisted chiefly of carbon dioxide, nitrogen and water.

• Volume I, page 367: A caption inquires, "Why do you think windmills are rarely used in the United States?" But windmills are far from rare in this country. Drive through the Great Plains and see for yourself.

• Volume I, pages 379 and 380: The discussion of fuel economy is based on the incorrect assertion that gasoline was far cheaper in the 1950s than it is now. The opposite is true. Indeed, the price of gasoline in the United States, expressed in adjusted dollars, is lower now than it ever has been before.

• Volume I, page 389: Sound energy is not purely kinetic. Like all wave energy, it is a combination of kinetic energy and potential energy.

• Volume I, page 406: "North America's first tidal generator began operation on a small inlet of [the Bay of Fundy] in 1985. Tidal energy is clean, renewable, and inexpensive." Inexpensive? Compared with what? The Bay of Fundy plant might have been commercially viable when the price of petroleum was about $25 a barrel, but the price of petroleum today is only half of that amount. Is the Bay of Fundy plant paying its way, or is it just a technological toy? The writers don't say.

• Volume I, page 407: "In California the Geysers has been operating since 1960 and produces enough energy to meet the needs of San Francisco and Oakland." This looks like a very poor effort to repeat some hearsay. The Geysers hasn't been "operating" or producing any energy, because the Geysers isn't a power plant: It is a geographical region that includes parts of two California counties. There are several dozen geothermal generating plants in the Geysers region, built at different times by a number of different corporations. The corporation that has made the biggest investment, Pacific Gas and Electric Company, once operated twenty plants in the Geysers, but only fourteen are still running. The six others have been closed because of depletion of the geothermal steam supply and because of problems involving corrosion and pollution.

• Volume I, page 511: The "Demonstration of the Coriolis Effect" is so fake that the student must rotate the terrestrial globe in the wrong direction to get the desired result!

• Volume I, page 529: "The gill covers of sharks are usually folds of skin, and sharks must therefore swim constantly." This is an inept attempt to recite the "fact" that sharks must swim continuously to force water over their gills, and that they will suffocate if they can't keep moving. That "fact" is a fiction. See "Deep Breathing" in TTL, July-August 1996.

• Volume II, pages 3 and 4: When the writers purport to tell about Francesco Redi's classic spontaneous-generation experiment, they misdescribe and misinterpret some of his crucial results. An illustration shows no maggots on the flasks that he had covered with gauze -- and according to the accompanying text, this signified that the generation of maggots was not affected by the presence or absence of fresh air. But what Redi actually observed was that maggots did appear on the pieces of gauze atop the flasks. Adult flies were drawn to the flasks by the odor of decaying meat, and they laid their eggs on the gauze because they could not reach the meat itself. Then, when the eggs hatched, maggots appeared on the gauze (and soon died of starvation). These were pivotal observations, for they demonstrated that the source of maggots is always flies, not meat. Sadly, this point has completely eluded South-Western's writers.

• Volume II, page 9: "A hypothesis supported by observation and repeated experiment may come to be called a theory." Wrong. To a scientist, a theory is not just a substantiated hypothesis; it is an elaborate construct which explains and links together a rather broad spectrum of observations. The kinetic theory, for example, is not merely an experimental corroboration of the idea that gases consist of molecules in constant motion. Rather, it is the intellectual construct that explains everything from the ideal gas law and our modern definition of temperature to the Dulong-Petit law of the molar heat capacity of solids.

• Volume II, page 36: Microelectronics, Teflon, and "metal alloys with a memory" are not spinoffs from the exploration of space.

• Volume II, page 84: Figure 4.34, which purports to show the voltage output of a DC generator, is in fact an oscilloscope display of a sawtooth wave produced by an electronic oscillator.

• Volume II, page 141: The writers confuse atomic mass with mass number.

• Volume II, page 152: Albert Einstein's famous paper of 1905 was not entitled The Special Theory of Relativity. Its title was On the Electrodynamics of Moving Bodies. The term "special relativity" was not used until 1915, when it became necessary to make a distinction between the 1905 theory and the new general theory of relativity.

Are these books acceptable for use in jurisdictions that have chosen an integrated approach to science instruction? I can only answer by saying: Caveat emptor. If a teacher is prepared to cope with the books' faults and to warn students about the errors that the books contain, the Science Probe series may be useful. Even in such a case, however, I would prefer to see students using books that paid more attention to quantitative matters and that did not ignore the most basic principles of the physical and biological sciences.

Returning to the "Biology"
That We Saw in the 1970s

William J. Bennetta

Seen in the light of evolution, biology is, perhaps, intellectually the
most satisfying and inspiring science. Without that light it becomes
a pile of sundry facts -- some of them interesting or curious but making
no meaningful picture as a whole.

Theodosius Dobzhansky (in his renowned article "Nothing in
Biology Makes Sense Except in the Light of Evolution," which
appeared in The American Biology Teacher for March 1973)

During the 1970s and 1980s, most of the high-school biology texts and middle-school life-science texts printed in this country offered a mangled, bogus form of "biology" that reflected the religious doctrines and demands of fundamentalists. Corrupt publishers -- e.g., Addison-Wesley, D.C. Heath and Company, the Macmillan Publishing Company, and Holt, Rinehart and Winston -- issued books which strictly concealed the fact that modern biology is a coherent science unified by the central concept of organic evolution. The books said nothing of evolution or the history of life on Earth, or they buried those topics under mounds of double-talk, equivocation and falsehood.

In many cases, the schoolbook-writers went out of their way to teach students that scientific statements about the history of life were nothing more than speculations. For example, Heath Life Science (1984) depicted the ancient dinosaurs as mere figments in which "Some scientists believe," and Scott, Foresman Life Science (1987) taught that no one knew whether ichthyosaurs and pterosaurs had really existed.

Some writers made vague allusions to evolution while replacing the word evolution with false synonyms, such as development or natural selection or even environmental change. Others mentioned evolution explicitly, but they presented it as an eccentric "theory" left over from the 19th century, and they taught that a theory was just an idle notion or belief. Still other writers -- like the ones who cobbled up Laidlaw's Experiences in Biology (1981) or Holt, Rinehart and Winston's Holt Science series (1986) -- rejected evolution entirely. They didn't mention the word, they didn't refer to the concept, and they categorically excluded the biology of the 20th century.

In the late 1980s, however, the major schoolbook-publishers sensed a demand for biology textbooks and life-science textbooks that would present some real science. Since then, they have undertaken -- with greater or lesser success -- to produce lots of new books which include conspicuous passages about evolution and the evolutionary histories of important lineages. Some of today's biology books even tell explicitly that evolution is biology's central organizing concept.

In South-Western's pair of Science Probe textbooks, we observe a return to the 1970s. South-Western's writers, evidently intent on pandering to fundamentalists, have excluded the idea of organic evolution from these books and have shunned any effort to teach real biology. They have merely made some haphazard efforts to cover some biological topics, and the results are aptly described by Theodosius Dobzhansky's phrase "a pile of sundry facts -- some of them interesting or curious but making no meaningful picture as a whole."

The zealous avoidance of evolution is particularly conspicuous in chapter 12 of Science Probe II, where the writers present a short passage about fossils. "Every period in the Earth's history," they say, "appears to have had its own characteristic collection of life forms. The fossils of these organisms provide important clues to finding the relative and absolute ages of rock layers."

The sentence about "Every period in the Earth's history" is silly and misleading. The writers don't know, or don't want to tell, that the periods are associated with characteristic complements of fossils because scientists have used fossils to define and delimit the periods. That every period is linked to "its own characteristic collection of life forms" is not a puzzle, is not a matter of chance, and is not something that merely "appears" to be so.

But what makes the entire passage ridiculous is that the writers refuse to acknowledge any modern interpretation of the fossil record, refuse to acknowledge any genealogical connections among the organisms of different periods, and imply that each period's "characteristic collection of life forms" originated de novo. If I were asked to cite a few examples of how unscrupulous writers turn important science into mystery-mush when they pander to creationists, I would certainly include the Science Probe passage about fossils.

In one of its ads for the Science Probe series, South-Western says that these books are "Aligned With The Science Education Reform Movement." The company does not provide any evidence to support that claim, and I myself am not aware of any "Science Education Reform Movement" which seeks deliberately to reduce biology to an unorganized mass of facts, or which denies that the Darwinian revolution ever occurred.

I can't imagine that any honest teacher would consider using these books, and I see no need to say any more about them.

Lawrence S. Lerner is a professor in the Department of Physics and Astronomy at California State University, Long Beach. His specialties include condensed-matter physics, the history of science, and science education.

William J. Bennetta is a professional editor, a fellow of the California Academy of Sciences, the president of The Textbook League, and the editor of The Textbook Letter. He writes frequently about the propagation of quackery, false "science" and false "history" in schoolbooks.

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