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4
Impediments to Implementing
Curricular Change: Texts, Tests,
and Classroom Practice
Although the committee is concerned about life-sciences education in
grades K-12, the focus of this chapter is the high-school level, because this
is where the most information has been gathered. Many, but not all, of
the recommendations we provide for reform at the high-school level are also
applicable at the elementary- and middle-school levels.
TEXTBOOKS
The Present Situation
With estimates that 75% of classroom time and 90% of homework time
involve the use of textbooks (Blystone, 1989), it is perhaps surprising that
deficiencies in textbooks have not been blamed more for the perceived problems
in high-school biology. Nevertheless, there are criticisms aplenty, and the very
diversity of their sources has become part of the problem. Criticisms have come
from biologists. Several analyses, either anecdotal (Gould, 1987; Paul, 1987) or
focused on a specific topic, such as genetics (Cho et al., 1985), have graphically
demonstrated how inaccuracies and confusion are perpetuated by textbooks.
Textbooks have also been criticized by persons who perceive a challenge to
their religious, social, or political views in the treatment of evolution or human
behavior. Publishers' attempts to placate religious critics have generated still
further negative reaction from biologists.
Are high-school texts truly useful to students and to teachers? Students
are discouraged by the overwhelming amount of material and the relentless
onslaught of technical vocabulary. The task of learning becomes a treadmill, a
daily but endless routine with no useful goals and little sense of accomplishment.
27
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FULFILLING THE PROMISE
Teachers often have to spend time decoding the texts a job made more difficult
by incomplete explanations and factual inaccuracies. Many students have to
rely on their texts, with little guidance from their teachers. Are the present texts
capable of sustaining students with little help from instructors?
How might we recognize good textbooks? Biology textbooks are in-
creasingly similar, but too little attention is paid to educationally desirable
characteristics. When individual textbooks are reviewed, they are usually com-
pared with each other, rather than with some standard (see, for example, AAAS,
1988~; and the general approach, clarity, accuracy, conceptualization, and flow
are rarely considered. Criteria for evaluating textbooks have been stated in
many forms (see Subcommittee on Instructional Materials and Publications
1957), but there is general agreement on the following seven needs. Although
we are not aware of a thorough recent review based on these criteria, we believe
that current texts fail in many respects to meet them.
Adequate but not encyclopedic coverage. Concern about the deliberate
omission of such central subjects as evolution and human sexuality is justified,
but many current textbooks were written with a compulsion to cover exhaustive
lists of terms and topics. The attempt to mention everything with or without
adequate explanations is a common deficiency of present texts. Its origin is
the publishers' correct perception that the current market demands it.
· Factual accuracy. This fundamental criterion is often violated. Inac-
curacy causes problems for students and teachers alike and raises concern about
the qualifications of the authors or the care in preparing the book.
· Incorporation of current conceptual understanding and new subject
matter. Many publishers add current experimental advances to their texts,
often set off in special boxes. But current conceptual understanding generally
is not incorporated into the deeper structure of a book and in the specific
explanations. Wrong impressions are given. Modern understanding generally
simplifies science, rather than complicating it. Good examples are the combina-
tion of cytogenetics with formal genetics and, more recently, the use of markers
based on DNA structure in genetic linkage analysis. Such subjects are usually
taught separately; as a result, the student fails to benefit from the simplifying
combination of fields.
· Logical coherence. Books written by single authors usually have a
logical coherence; multiauthor books often seem like compendia of separate
and disconnected segments. If we expect a student to gain increasing mastery
of a subject, the subject must unfold with appropriate reference to earlier parts
and repetition of older themes. A textbook should be readable and interesting.
That is the hardest trait to define and judge, but a common reaction of a
knowledgeable person perusing textbooks for the first time is that most fail
badly in presenting a coherent point of view and vision of a given subject. The
failure is communicated to students, who are understandably bored.
· Clarity in explanation and electiveness of illustrations. Textbook
publishers have emphasized illustration, and the amount and elaborateness of
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29
illustrated material have increased faster than the number of words in the text.
Yet many illustrations are mere decorations-they convey no information, they
are often poorly integrated into the text, and they fail to explain.
· Appropriateness to students' level and interest. "Appropriateness" has
usually been interpreted as not overestimating the students' interests, reading
abilities, and capacities for higher thinking, with little thought about positive
educational goals, such as understanding of the material. As a result, most
texts emphasize rote learning of an alien vocabulary without regard for the
likelihood of understanding. As texts have grown in size, the numbers of
subjects mentioned have also increased. To make their textbooks suitable for
students, publishers should emphasize the teaching of a few important concepts
and attend to such pedagogical elements of writing as the proper definition and
economical use of terms, the appropriate repetition of important concepts, and
the integration of text with laboratory exercises.
· Representation of biology as an experimental subject. Textbooks
should explicitly convey to students that the information presented is the result
of experimentation and that understanding is constantly being refined and is
must yield.
subject to change as new experiments are conducted. Textbooks should also
describe the nature of experimentation.
To what extent is the poor achievement of our students in biology a
reflection of poor explanations in biology textbooks? Textbooks are only part
of a much larger problem, but the lack of sound conceptual bases, the annoying
and propagated errors, and the almanac-like organization of material all suggest
that the authors' own level of understanding is insufficient to permit effective
presentation.
Books need to convey a vision. Furthermore, biology has matured as a
discipline, and it is not possible to add new subjects, such as molecular and cell
biology, and keep the level of detail on traditional subjects, such as systematics.
Similarly, if one wants to teach ecology as a quantitative subject, other subjects
The effort by publishers to mention every subject aimed at
satisfying every conceivable textbook adoption committee has produced books
that do not reflect a satisfactory understanding of any subject. The effect is
to introduce numerous barely defined terms, many of which are redundant,
imprecise, archaic, and not often used by practicing biologists. To select an
arbitrary example, how many scientists now know or care about the specific
terms used to identify the morphological stages of meiosis? What is essential is
the nature of the processes that are occurring. Similarly, important distinctions
can be drawn between endocytosis, pinocytosis, and phagocytosis, but students
would be better served by a topological understanding of the cellular traffic of
membrane-bound organelles than by memorizing these distinctions.
The most serious deficit in current textbooks is their authors' lack of
conceptual understanding of their discipline. Biology now has much of the
elegance of classical physics. At the level of the cell, common mechanisms
are at work in signaling across cell membranes, in organizing the structure of the
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cell in cell division or in causing the cell to move, in converting the energy of
sunlight into sugars or in the oxidative metabolism of glucose, and in regulating
genes in either bacteria or humans. Variation and selection are at work not only
in evolution, but in the immune system. Evolution has left its footprints in the
structure of DNA and in the strategies of development, and these concepts are
important not only in bolstering our understanding of evolution, as introduced
by Darwin, but in shedding light on human biology.
The presentation of biology as an experimental subject goes beyond the
textbook into the whole curriculum and in particular to laboratory exercises.
There is clearly a tension between the demands for textbook comprehensiveness
and the limitations of textbook size. The usual casualty is the presentation of
biology as an experimental science. In that respect, the books merely amplify
the growing pressures of tests and curricula to de-emphasize the process of
discovery and to portray biology as the worst kind of literature-all characters
and no story.
In summary, current biology textbooks are an important part of the failed
biology curriculum. They are often not selective in what they present and lack
both a broad conceptual basis and a refined understanding of specific subjects.
They emphasize memorization of technical terms. They have many misleading
and superfluous illustrations. The books are different, but a tendency toward
uniformity and mediocrity can be seen in recent years.
Forces That Shape Textbooks
The open and competitive American marketplace for books might seem
to be a guarantee against mediocrity in biology textbooks. Nothing could be
further from the truth. In her book A Conspiracy of Good Intentions, Harriet
Tyson-Bernstein (1988) has lucidly described the interplay of interests at work
in the generation of textbooks for public schools. The publishers assert that
to survive in the market they must compete effectively in the large "adoption
states" notably California (primary schools only) and Texas that periodically
approve texts for use in their classrooms. Playing on the notion that textbooks,
even science textbooks, should conform to local social and religious values,
small groups have been able to dictate changes in the content of books before
state approval. That phenomenon achieved prominence a few years ago in
the case of the treatment of evolution, and recent events in California have
demonstrated that it is still alive. Moreover, we are likely to see it in other
guises as efforts to teach young children more about human reproduction
increase and as animal-rights activists increase their public presence.
Influences from outside the education community, however, are only the
tip of the iceberg. Biology books mention large numbers of terms in response
to specifications that publishers get from the states. The specifications appear
as lists or outlines that are formulated with vague goals or with state or national
examinations in mind. Conversely, the examinations might be written with the
textbook specifications in mind. Either way, the education community must
bear a large measure of responsibility for the characteristics of textbooks.
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31
Publishers are often required to produce a new book in only 6 months
or so (Tyson-Bernstein, 19881. In part for this reason, they turn to groups of
writers (commonly anonymous), who separately draft small sections of a book.
For crafting a coherent textbook, this is a formula for almost sure disaster.
Some of the most memorable textbooks (albeit not for high schools) were
written by individual authors, for example, E. B. Wilson's Cell in Development
and Inheritance (first publication in 1896), James Watson's Molecular Biology
of the Gene (1965), and Linus Pauling's The Nature of the Chemical Bond
(19391. Each of these authors had a single vision-perhaps idiosyncratic, but
economical, unified, and clear. Writing textbooks is one of the most difficult
challenges that scholars face, and even some of the most brilliant have failed.
It is hard to see how the present manner of writing, often using panels of
nonexperts pursuing questionable educational goals, can succeed.
The current method of writing textbooks is illustrated in the preface to the
teacher's edition of a widely used high-school biology textbook:
The modern biology program was developed in conjunction with a thorough
program of research and testing. The objective of this research and testing
was to survey the wishes and concerns of American teachers of high school
biology and to reflect those wishes arid concerns in the various components
of this program.
Of
The publisher designed the text around "focus groups" that each consisted
a moderator and about a dozen teachers from local high schools. The
moderator showed the teachers various prototypes for the design of the table
of contents, the writing style, and many other aspects of the book. The
teachers responded, and representatives of [the publisher] noted the teachers'
concerns and then modified the components accordingly.
Note the casual use of teachers, the absence of input from practicing scientists,
and the parody of research and testing.
The next step is usually a national market survey. Because study (Weiss,
1987) has shown that 76% of classroom teachers are satisfied with the available
books (a serious problem in itself), one is reminded of the commercials for beer
in which it is revealed that those who drink a particular brand are found to prefer
that brand. There is neither time nor incentive before full-scale production to
field-test textbooks under conditions that might expose their weaknesses and
lead to revision. (That constraint should be compared with the extensive testing
of the biology texts first produced by the Biological Sciences Curriculum Study,
BSCS, in the 1960s.)
The number of illustrations, the use of color, and costs are increasing for
both college and high-school texts (Blystone, 1989~. But to what purpose?
Despite the emphasis on illustrations and their obvious technical quality, the
pictures often fail to inform. A striking demonstration is the reproduction in
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the Holt text (1989) of a 1961 Scientific American portrayal of the cell, which
now appears in color and three dimensions, but with no change in substance.
But during the intervening quarter-century, our understanding of cell structure
changed dramatically in ways that are useful for understanding cell movement
and cell differentiation. Illustrations like this therefore perpetuate incorrect or
incomplete concepts.
Illustrations often are not integrated with the text and are not easy to
follow. Sometimes they are absurd, as when electron micrographs, which have
no natural color, are shown in color. Many illustrations seem to come directly
from the scientific literature and are too complicated for high-school students
to understand. Does the publisher believe that they give a book an authority
that would otherwise be absent? The main function of illustrations appears to
be to impress prospective buyers, but in many new texts illustrations are often
only decorative distractions.
In summary, most biology textbooks are produced by publishers who
are responding to educationally bankrupt market forces. They are written by
authors who do not control the content of the books and who are not selected
for their knowledge of biology. They are then edited to conform to grade-
level readability scores and to accommodate local tastes and religious views.
Whatever the educational merits of editing for grade-level readability, even the
most casual reading of texts suggests that they are edited by people who know
so little of the science that they introduce inaccuracy and confusion. Last,
but not least, the current textbooks are not interesting; they fail to convey the
fascination and wonder of living systems, thereby convincing many students
that the study of biology is an onerous task.
How Can Things Change?
The problem of biology textbooks intersects with a number of other issues
discussed in this report. If textbooks are to improve, there needs to be a
greater emphasis on the place of concept and process in teaching biology and a
clarification of the goals of science education in the sweep of years embraced
by K-12. Achieving that emphasis will need consensus among teachers (as
described in the section of the report on teacher preparation), changes in how
we measure student accomplishment (as described in the section on testing),
and changes in the expectations that state boards convey to publishers about
texts. If those changes can be accomplished, publishers will find it in their
interests to produce better texts.
Improving textbooks is a national problem that requires national leadership.
In Chapter 8, we propose the creation of a body that could address the problem
of textbooks in ways set forth below.
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33
Recommendations
· A process of review of high-school texts that is open to the scrutiny
of scientists should be instituted. Whatever their pedagogical merits, text-
books need to be examined for scientific accuracy, interest, currency, and
vision by scientists and outstanding teachers in a forum where the reviews
will be widely available to teachers, members of school boards, and others
at the grass-roots level. That is, the broader scientific community should be
engaged nationally in collaboration with teachers in evaluating textbooks
and locally in providing advice in textbook adoption. It is important that
teams of reviewers include research scientists, teachers with experience
in the school classroom, and individuals familiar with recent research on
learning and on reading comprehension.
A fuller examination of present texts for conceptual and factual errors
would document further the need for change, enumerate principles that
should be stressed in texts, and provide incentives to publishers to alter
their mode of production. If conditions can be created in which reviews
of books by scientists are truly influential in the processes of adoption,
it will become not only possible but necessary for publishers to produce
educationally worthy textbooks.
· We need to explore ways in which first-class scientific minds can
be engaged in the writing of high-school texts and the control of content
can be shifted from publisher to author. We make this statement on the
assumption that publishers will welcome serious discussion with scientists.
We recognize that good books need not be written by individual authors;
in fact, the team approach used by the BSCS, in which research scientists,
science educators, and talented secondary-school teachers worked together,
has a great deal to recommend it. What is essential is that the right
people are involved and that enough time is devoted to the project to allow
adequate classroom testing and analysis before books go to press. We
could also see a fruitful collaboration develop between a foundation and
a publisher for the development of a new text, but if such a project is
launched, great effort should be made to see that the mistakes of the past
are not repeated.
· A new biology text should be much smaller than most of those
now on the market. It should be designed around important biological
concepts and principles and should cover fewer topics in greater depth.
Moreover, it should be interesting to student and teacher alike. Technical
language should be used sparingly and never as a substitute for lucid
explanations of biological processes. In the design, writing, and editing of
a book, the results of research on reading comprehension should be used
fully. Illustrations not only should be accurate, but should be designed
to promote understanding. Their conception must be part of the authors'
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FULFILLING THE PROMISE
creativity, and they should not be left for editors and art departments to
select. Illustrations that only decorate and distract do nothing to train the
mind.
· The committee has considered and rejected alternatives to text-
books, such as booklets and videotapes. Although booklets could be topical,
could be written by experts, and could be more readily revised than full-
length texts, their disadvantages are considerable. The very perishability
of loose-leaf or pamphlet formats would impose a cost that most school
districts would find unacceptable. Resources that treat selected topics can
be very effective in the hands of skilled teachers who are able to provide
a conceptual framework to bind the course together, but we are skeptical
that most teachers are ready to assume such responsibility for a course of
the kind we believe should exist. Textbooks will continue, at least in the
near term, to play a central role in most high-school classrooms in the
United States.
For videotapes and computer programs the considerations are sim-
ilar. Although we favor the development of appropriate videotapes and
software, we see these materials as playing only supplementary roles in
the classroom. Books, however, represent a resource that students should
learn to respect and use throughout their lives. In addition, the facilities
for using videotapes and computer software are not universally available
in American classrooms. Even if they were, there is little likelihood that
videotapes and software of suitable quality and quantity could be produced
in a short time. In the near term, however, videotapes and computer soft"
ware could become very effective tools in teacher inservice programs, in
addition to their supportive role in the classroom.
This nation has a tendency to try quick technological fixes for national
problems, but the solutions to our educational dilemma will not be found in
that quarter. Good teachers are the key. We must look to teachers to provide
instruction in science to our young people, and in this our teachers need
enormous help and support. We must see that they are assisted by the best
possible textbooks and not delude ourselves with the hope that merely putting
teaching materials in new types of packages or on video screens will prepare
our young citizens for the next century.
LABORATORY ACTIVITY
The Importance of Laboratory Activity
Biology offers unique opportunities for students to observe and think about
living organisms directly. Nevertheless, the study of life finds students mainly
listening to lectures and reading most of each week, week after week (Stake
and Easley, 1978; Mullis and Jenkins, 1988; Weiss, 1989~. Similar trends at
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35
the undergraduate level are adversely affecting the preparation of new biology
teachers (Merriam, 1988).
The laboratory serves several crucial functions in the students' intellectual
development. First, appropriately designed laboratory activities can challenge
students' beliefs about the natural world and lead them to struggle with alter-
native ideas until they can present scientific concepts accurately in their own
words. The effectiveness of that mode of learning was implicit in some earlier
approaches to the laboratory, was reinforced by the work of Piaget, and has
more recently been broadly supported by findings in cognitive psychology (see,
for example, West and Pines, 1985; Linn, 1986; Resnick, 1987~. Observation
requires hypothesis and theory; without this framework, one does not know
what to observe (Frank, 1957~. Exposing students' beliefs is important, for
naive theories, once exposed, can be made explicit and then tested through
further observation and experimentation.
Second, laboratory investigations can enable students to generate knowl-
edge directly from natural phenomena and learn how such knowledge can
become reliable knowledge. It is in the laboratory that students can learn the
power and characteristics of biology as an experimental science. Laboratory
work and field work that are done effectively can enable students to understand
scientific ways of knowing and the differences between those ways and other
sources of knowledge.
Third, direct hands-on experience produces lasting memory and, if properly
reflected on, can lead to deep understanding of organisms and their environ-
ments. Part of its benefit is motivation, because it is generally more interesting
to study organisms directly than to read about them. Another benefit is en-
gagement. Students can be involved in reading and listening, but participatory
involvement with objects and events is more effective.
Fourth, laboratory activity can help students to learn about precision and
accuracy in observing, in record-keeping, in measuring, and in inferring. It can
help students learn that the need for precision varies with human purpose.
Fifth, laboratories and field studies can involve students in solving prob-
lems: defining a problem and stating it as a hypothesis to be tested, determining
what and how much evidence is required to make probable or to falsify the
hypothesis, controlling variables, learning to use apparatus and techniques to
gather valid information, assessing the sufficiency and validity of data gath-
ered, making inferences and interpretations within the limitations of the data,
and subjecting the interpretations to the criticism of peers and others (see, for
example, the use of discretionary laboratories in Leonard et al., 19811.
Finally, laboratory activities have the potential of introducing students
to different technologies measuring instruments, laboratory apparatus, and
electronic equipment and making them comfortable and skilled in using these
tools in the quest for new knowledge. (Budgetary restraints will limit the degree
to which this potential can be realized in high schools.)
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In science, business, industry, and government, tools and technologies
are integral to the workplace. Students must have experience with as many
technologies as can be made available in the school setting and, even more
important, be provided with opportunities to measure, observe, and infer in
solving problems. In summary, laboratory activities can effectively help students
to grapple with challenges to their beliefs about natural phenomena and to
construct new conceptualizations (Novak, 1988~. To attain this overriding
outcome, laboratory activities must have personal meaning for each student. As
means to this end, laboratory activities should enable students to:
· Formulate problems, devise methods for investigating problems, and
solve problems individually or as team members or leaders.
· Deliberate thoughtfully with peers and adults about the outcomes and
meanings of investigations and reinvestigate to resolve conceptual contradic-
tions.
· Understand the limitations of small numbers of observations in gener-
ating scientific knowledge.
.
Distinguish observation from inference, compare personal beliefs with
scientific understanding, and comprehend the functions of hypothesis and theory
in science and how theories are developed and tested.
Select appropriate apparatus and use it with skill in conducting inves
.
tigations.
· Develop familiarity with organisms and an interest in natural phenom-
ena and acquire the knowledge and skills necessary to increase this interest.
Current Failures of Laboratory Instruction
The promise of laboratories has not been realized. The typical laboratory
activity is a "cookbook" exercise that students can "do" with little intellectual
engagement (Tobin, 1989~. Although laboratory work is second to lecture,
accounting for about one-fifth of class time in tenth- to twelfth-grade sci-
ence classrooms (Weiss, 1987 biology was not reported separately), it does
not appear to contribute much to student understanding of biology, which is
unimpressive (Mullis, 1989~.
The use of laboratories in teaching biology is limited and has been de
clining nationally for years (Stake and Easley, 1978; Mullis and Jenkins, 1988;
Weiss, 19891. The decrease has occurred despite the major work done by the
BSCS in developing investigative (as opposed to illustrative) laboratory activ-
ities, both in the three versions of its biology texts and in its laboratory block
and second-course programs (Mayer, 1978~. Several factors are contributing
to the decline: the decrease in school resources for educational supplies and
equipment; teachers' feeling that more time is needed to cover textbooks of
increasing length; lack of adequate laboratory experience in teachers' prepa-
ration, especially in college biology courses; length of the classroom period;
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37
requirements that teachers move from room to room during the day; the time
required for effective laboratory investigations; class sizes that are larger than
laboratories and classrooms can accommodate; the lack of space in classrooms
to facilitate extended laboratory investigations; inadequacy of funds for buses
and substitute teachers for field trips; complaints of other teachers if students
are away from their classes for field studies; and the logistics involved in having
busy teachers, with too many students and different class preparations, care for
and provide materials for classroom use (Stake and Easley, 1978; Hofstein and
Lunetta, 1982; Tobin and Gallagher, 1987; Novak, 19881. Finally, laboratory
work and field work reduce control of student behavior and can present disci-
plinary problems, which might be especially difficult for inexperienced teachers
or in situations where students do not find meaning in what they are doing.
The goals of laboratory activity are not easily achieved, for without careful
design and appropriate discussion of findings, students become confused and
discouraged. For example, in a recent study of what constitutes successful lab-
oratory work, Nachmias and Linn (1987) found that students accepted jagged
graphs that described results obtained with insensitive instruments as reflecting
the nature of cooling and heating. The explanation that the shape was caused
by instrumentation failed to influence the students' explanations. Only when
the phenomena were explored in depth with much discussion by students,
with student-student and teacher-student questioning, and with explicit instruc-
tion designed to help the students to link laboratory information and graphic
representation with their knowledge of the natural world-did students develop
"a fairly complex understanding of the interrelated factors that influence the
smoothness of a heating or cooling curve" (Nachmias and Linn, 1987, p. 503~.
Smith and Anderson (1984) came to similar conclusions in their study of
experiments on respiration and photosynthesis. After traditional experiments
with plants, students retained their naive concepts of food, respiration, and
photosynthesis. Ten carefully structured laboratory experiments with extensive
and carefully planned discussion and questioning of each experiment were
required to achieve conceptual changes in which naive views of food were
replaced with biological understanding.
Conclusions
Properly designed laboratory experiences are essential for effective high-
school biology courses. The prevalent form of laboratory activities, which
merely illustrate what the text has presented, do not produce the desired results
and should be replaced with genuine investigations, designed and tested to
enable students to achieve the conceptual changes necessary for intellectual
development and understanding. Laboratory work and field work are therefore
central to a major reconstruction of high-school biology education.
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for words and definitions instead. Standardized questions that merely require
simple recall or name association are of little value to either teachers or students.
For example:
The
is the powerhouse of the cell.
a) cell membrane
by golgi apparatus
c) mitochondrion
d) nucleus
A "correct" answer to this question in no way conveys an understanding of the
important role the mitochondrion plays in cellular respiration.
Standardized tests are generally norm-referenced, which means that they
are developed to produce a distribution of scores, preferably a normal distri-
bution. Questions that everyone answers correctly or that everyone misses are
eliminated. Questions that are answered correctly by 30-70% of the examiners
yield the best "reliability" scores. "Reliability" of a test is the degree to which
the same score would presumably be obtained by a person if that person were
tested again-it refers to the stability, dependability, and predictability of the
test. Reliability is affected by the length of the test; in general, longer tests
yield higher reliability. Because norm-referenced tests are designed to sort
students on a normal distribution, the mean, median, and mode can shift if
students do better or worse, but about half the students will always be "below
average." Furthermore, research clearly shows the negative effects of normative
grading on learning, motivation, and achievement (Eisenhardt, 1976; Robinson,
1979; Crooks, 1988~. There is something pernicious and destructive if pride
of accomplishment must be tempered by the belief that one's performance is
always "below average."
The contents of standardized tests are developed from the major texts
and curricular guides used throughout the United States and are presumably
independent of the particular curriculum and instruction of any school or school
system. Norm-referenced standardized tests offer efficiency in scoring, yielding
numerical scores with high reliability; but they usually sacrifice validity (C.
W. Anderson, 1989~. "Validity" refers to the degree to which a test measures
what it was designed to measure for our purposes, understanding of science.
Standardized tests rarely assess the application of knowledge, problem-solving,
or the ability to think through issues that involve biological understanding. The
tests, therefore, sort students, but on a scale that deflects judgments about the
effectiveness of the curriculum. Students who score well on these tests might
discover in college or elsewhere that they have been rewarded without real
learning.
An alternate to the norm-referenced test is the criterion-referenced test,
which is used by many states to measure competence. Such tests consist
of items related to specific objectives and generally incorporate, for a group
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43
of items or the whole test, the criterion of acceptable success. Establishing
the criterion of acceptability is essentially arbitrary for example, correctly
responding to 70% of the questions. Test items like those administered by the
NAEP are scaled to provide a criterion-referenced interpretation of levels on a
continuum of proficiency (Mullis and Jenkins, 1988~.
Selection of items for either type of test involves judgment, and it would
be a mistake to assume that criterion-referenced tests address all the deficiencies
of norm-referenced tests. Many items can measure the same concept and vary
in difficulty. One cannot assume that test scores indicate accurately the degree
to which a concept has been mastered, merely on the basis that the test was
criterion-referenced, rather than norm-referenced (Klein and Kosecoff, 1973~.
Teacher-Made Tests
Tests can also be composed by individual teachers, and they might or
might not include essay or other types of problems in addition to or in place
of multiple-choice items. Such tests differ little from those given 30 or 40
years ago, except that fewer essay and more multiple-choice tests are used
now. Examination of teacher-made tests indicates that, for the most part, they
measure recall of isolated facts in a multiple-choice format (Robinson, 1989;
Stiggins et al., undated). In design, tests made by teachers tend to follow the
format of standardized tests.
The Educational Impact of Tests
The role of tests has been examined by many others. For example,
in an extensive review, Crooks (1988) found that evaluation of students in
the classroom appears to be "one of the most important forces influencing
education." He found (p. 467) that classroom evaluation guides students'
judgment "of what is important to learn, affects their motivation and self-
perceptions of competence, structures their approaches to and timing of personal
study (e.g., spaced practice), consolidates learning, and affects the development
of enduring learning strategies and skills."
A panel of the National Research Council (NRC) convened to review
science tests concluded that the multiple use of single tests has led to the misuse
of results (Murname and Raizen, 19881. Specifically, the panel recommends
that:
.
Results from tests constructed for one purpose not be used for a quite
different purpose.
· School or classroom average test scores not be applied to individuals
and individual test scores not interpreted as ratings or rankings of persons, but
only of performance on a test that assesses specific skills.
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FULFILLING THE PROMISE
.
Test results or tests of the kind reviewed by the NRC panel not be used
as the major force driving curriculum and instruction.
Testing clearly plays important roles in education. Testing can help to
motivate interest and generate enthusiasm for a subject, or it can smother
interest and deaden curiosity. Testing can help to evaluate the success of
programs, or it can drive a curriculum in the wrong direction. We are deeply
concerned that the present system confuses the multiple roles of tests, to the
detriment of education.
With the recent press for accountability from national, state, and local
agencies, testing programs are beginning to drive the curriculum. Teachers
feel compelled to limit their efforts in the classroom to what and how school,
district, or state tests assess. "Teaching to the test" is increasingly prevalent in
high-school biology classrooms, as was vigorously expressed by many teachers
in this committee's open forum during the November 1988 meeting of the
National Association of Biology Teachers in Chicago.
Dependence on norm- or criterion-referenced multiple-choice tests as they
are currently constructed, either for grading students or for analyzing and
creating educational policy, tends to misdirect students' habits of study. Rather
than mastering concepts, students believe that recognizing terms in a multiple-
choice format is the appropriate educational goal. This kind of testing has a
major impact on how students go about studying and on the strategies they
acquire for learning (Crooks, 1988~. In the long run, the impact of current
modes of testing on enduring skills and strategies for learning will be inimical
to reform. We cannot overemphasize the importance of this relationship.
Resnick and Resnick (1985) make a strong argument for moving from
standardized testing to a system of examinations designed to assess particular
courses or curricula-examinations created for specific situations. Although
in principle such test instruments could be norm- or criterion-referenced, a
1986 project of the NAEP (Blumberg et al., 1986) showed that ensuring that
higher-order thinking skills (such as problem-solving) are assessed requires that
students be interviewed by knowledgeable adults about responses to problems.
Similar results were found in the United Kingdom after more than 7 years of
work by the Assessment of Performance Unit (Driver et al., 1964~. (For an
alternative view, see C. W. Anderson, 1989.)
In the preceding section, we argued that laboratory work and field work
are essential parts of an effective education in biology. However, there are
few documented instances of the use of practical laboratory tests in biology
(Robinson, 1979; Gallagher, 1986~. In light of traditional testing practices, it
is not surprising that little is known about the effects of laboratory work on
achievement in high-school biology. Tamir and Glassman (1970) found differ-
ences between student scores on a 2-hour practical examination and teachers'
grades; the practical examination seemed to be measuring something different
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45
from what was covered in teachers' evaluations. Similarly, Robinson (1969)
found a low correlation (r = 0.3) between a laboratory practical examination
and a multiple-choice test on similar material. Failure to develop new test
instruments to assess properly the outcomes-cognitive and affective, theoreti-
cal and applied-of education in biology and especially of the contribution of
laboratory work in biology in the current school and university climate could
further reduce the commitment of staff and institutions to reform teaching and
learning.
Conclusions
Citizens who lack knowledge and understanding are susceptible to those
who confuse science and other ways of knowing, to the detriment of public
understanding and rational decision-making. Understanding of central concepts
and principles of biology will not be gained as long as classrooms and stan-
dardized tests assess only recall and recognition. Tests that are consistent with
a new commitment to understanding in depth are essential to enable teachers to
know what they are accomplishing as they change their teaching methods and
emphases. They are also necessary to inform students that different learning
strategies are needed to achieve the goals of the biology course.
The fundamental problem faced by evaluators is that they do not have
adequate test instruments to determine whether students can use biological
knowledge or whether some ways of teaching and learning are more productive
than others. For the same reason, we also are not able to determine which major
changes in teacher education would be most effective in changing students'
achievements. Lack of instruments and methods that permit students to display
what they have learned in a year of high-school biology limits the improvement
of biology education. In addition, testing is increasingly driving curriculum
and instruction in a dull and pedantic fashion, and that makes it imperative to
address the issue of testing and evaluation in middle- and high-school biology
at all levels national, state, school district, and classroom.
If major changes are made in the curriculum, in instruction or teacher
training or both, existing instruments will be too blunt to show differences
in students' achievement in understanding, skills, or attitudes toward science.
Continued use of the same kinds of assessment instruments and procedures that
are now commonly used could lead to a worsening of the present situation,
even in the name of reform. New outcomes and expectations could be nullified
by outdated standards.
A whole new array of test instruments and procedures should be developed
to enable biology teachers to evaluate and improve their teaching and their
students' learning. Means should be designed specifically to address how well
schools are doing. Instruments should:
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· Serve an educational function for students, helping them to understand
their own progress and providing the necessary measurements required by
others.
Inform students of their ability to apply randomly selected biological
principles and concepts to real problems personal, societal, and global.
· Inform communities and the profession about the range of capabilities
that students have developed in solving problems, as well as their attitudes
toward biology and its relevance to their lives and their future.
Require the use of scientific apparatus and procedures, such as labora-
tory practical examinations.
.
Rev Hash. anal administrators in their critical inquiries into the
quality of biology education by measuring the range of conceptual capabilities,
attitudes, and skills exhibited by students.
Such instruments and procedures should be sensitive enough to display dif-
ferences in students' performance with changes in teaching and learning. If
appropriately developed, such tests might drive the curriculum, but in ways that
are in the best interests of students.
Recommendations
Several kinds of tasks need to be carried out by classroom teachers
and school districts, states, and the nation. We do not need a national test,
but rather tested models and problems that can be used for the assessment
of biology education at district, state, or national levels. Testing research
and technology have advanced to the point where they can make important
contributions to biology education. The American College Testing Program
(ACT) and the Educational Testing Service (ETS) seem to be developing new
assessment methods, and the trend is encouraging. We have several specific
recommendations, as outlined below:
.
A major effort is needed to develop, test, and publish model exam-
inations, as well as sample questions and procedures to assess the desired
outcomes of biology education-cognitive and affective changes and theoret-
ical and applied knowledge. The examinations must be especially sensitive
to the contribution of laboratory work in biology. They should use any
technology that would enable measurement of the most essential outcomes
of biology education as described throughout this document. Different tests
should be designed for use at different levels-e.g., middle school and high
school. They should serve more than traditional functions by involving
students in thinking and reasoning (Haney, 1984~. Test-makers should
consider the work of Blumberg et al. (1986), the Assessment Performance
Unit in the United Kingdom (Driver et al., 1964), and other literature on
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47
assessing performance (Stiggins, 1987; Eylon and Linn, 1988). In addition,
continuing evaluation of the NABT/NSTA High School Biology Examination
(a product of collaboration between NABT and NSTA) with a view to how
these goals might be achieved is desirable. The utility and effectiveness of
new tests should be examined by analyzing patterns of performance, rather
than single numerical scores.
A national group of biology teachers, biologists, teacher educators, and
scholars in educational and cognitive psychology and measurement should
be funded to collaborate in the development, testing, and implementation
of new examinations. Teachers involved in the project should be released
from some of their teaching responsibilities to permit direct involvement in
this critical effort in instructional improvement.
Once the materials are developed, pilot programs should be created for
introducing preservice and inservice biology teachers to their appropriate
use. A larger number of biology teachers and college professors who teach
methods courses for biology teachers should be involved at this stage. After
testing, the programs should be disseminated into many classrooms, with
carefully designed research to demonstrate appropriate use and warn of
problems that attend misuse of the materials and their adaptations.
· A second initiative is needed to improve tests given regularly by
biology teachers during the school year. Unless teachers are helped to
construct measuring instruments that are consistent with the best practices
and the agreed-on goals of biology education, their classroom tests will
lead students to continue to cram for tests that require mere recognition of
terms.
This second project should follow the first when there has been enough
time for the results of the first to be assessed. During development and
field testing, the project should involve classroom teachers, university
biologists, and persons knowledgeable about testing procedures. It should
include the development of a series of problems designed to assess students'
understanding of major biological concepts and ability to apply them. An
appropriate outcome would be the creation of a package of widely avail-
able training materials that might include a video tape or disk, computer
software, and examples of how to analyze patterns of responses to related
items.
· The publishers of tests that accompany textbooks and other learn-
ing materials need to improve the diversity and quality of their tests.
Teachers have come to expect test booklets to accompany textbooks. Be-
cause there is no market advantage to testing the quality of the tests, they
do not constitute priority investments for publishers, and the schools' ready
acceptance of them is a commentary on the low priority attached to testing.
Efforts need to be pressed to enlist the cooperation of university
biologists, teachers, science educators, and publishers in improving, through
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field testing, the assessment materials that accompany textbooks. Informa-
tion on testing conditions, instructional goals, relation to the text materials,
and ranges of student performance should be published in standard reports
that accompany textbooks. Unfortunately, given the markets in which pub-
lishers swim or sink, we cannot be sanguine about the likelihood that they
will meet this challenge until the expectations and practices of teachers and
schools are substantially altered.
· States and school districts should move swiftly to recognize the need
for new tests. Low-quality tests or tests that are not based on appropriate
educational goals should not be accepted from publishers. States and
school districts should avoid using results of paper-and-pencil tests as the
sole criterion of the effectiveness of their biology programs. Tests that are
developed locally should go through a careful process to ensure their validity
for assessing the outcomes of biology education with respect to essential
goals. Several indicators (measures that allow a judgment to be made as
to whether a given condition is getting better or worse), as described by
Murname and Raizen (1988), should be included with test results when the
results are reported. It is essential that indicators be related to student
understanding, be operationally defined, and be kept with test results year
after year.
The processes of evaluation cannot be addressed in isolation from what
is in textbooks, how teachers are taught, the conditions under which teachers
work, and public consensus about the goals of science education. Moreover, as
science changes, educational goals must be tuned. Biology is a rapidly changing
field of study, posing conceptual shifts and generating new social and ethical
issues. The issues raised by testing and evaluation cannot be solved without
persistent, continuous attention by a broad spectrum of experts.
In addition to the interdependence of testing, textbooks, preservice pro-
grams, and inservice programs, there is a second compelling reason to look at
testing with a fresh eye: the purposes of norm-referenced testing do not serve
the goal of improving teaching and learning. We need a national perspective
concerned more with evaluating the effects of curricula, teaching methods, and
materials than with ranking the performance of individual students. We need to
develop ways to probe the system's components, rather than the relative ranks
of the learners. Existing institutions with a role in testing are not designed to
pursue that objective by themselves.
In Chapter 8, we propose a formula that is free of constraint from govern-
ment, business, or any other constituency, but calls on the scientific-research
and educational-research communities for valid judgments that will be helpful to
biology teachers, parents, administrators, school boards, and state departments
of education.
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OTHER FACTORS THAT HINDER EFFECTIVE EDUCATION
49
Effective teaching of biology or any other subject requires a broad and
deep knowledge of the material to be taught, instructional skills, a willingness
to give of oneself to others, and a commitment that continues after the last child
leaves the classroom for the day. In short, teaching is a profession. Among
the problems that beset teaching, however, are the nonprofessional burdens that
teachers in many schools must bear. Most of those burdens reflect ills in the
larger society, but they are often manifested in the classroom, where teachers
are not prepared to deal with them. Pernicious problems-such as the sale
and use of illegal drugs and the violence that accompanies them, pregnancy of
teenagers, and high dropout rates are becoming endemic in the nation's public
schools.
The professionalism of teachers is further vitiated when, in addition to
responding to continual crises in the classroom, they are expected to respond to
political pressures for accountability and cost-effectiveness. With the increasing
public clamor for educational reform, what passes for leadership has all too often
fallen solely to politicians, and authority is increasingly centralized in district and
state offices of education. That trend has furthered the loss of professionalism
among teachers, as decisions about textbooks and objectives have been removed
from their control and pressures to teach to examinations have increased. But
results of research indicate that the combination of autonomy of schools and
teachers with parent participation is the key to high academic achievement
(Chubb, 1988), a standard indicator of successful teaching.
A great disparity exists between the goals of teaching and the possibility
of reaching those goals in the present teaching environment. The reality of the
teaching environment does not bode well for the current wave of educational
reform. Within schools, for example, state or local policies often impede
effective science teaching. If classrooms have 30 pupils, teachers might have to
relate to 150 different children each day. Many classrooms must be shared by
teachers, and a teacher must go elsewhere for some periods. Typically, periods
are a rigid 45 minutes long, and there is no opportunity during the working
day to set up a classroom for laboratory activities. Laboratory facilities, if
they exist, are underfunded. Under those circumstances, it is nearly impossible
to teach science to students in a manner that is not built around workbooks,
lectures, and memorizing.
The absence of time for anything but the minimum makes creative teaching
difficult. There is no time to prepare or to reflect and no released time to attend
workshops and conferences, to visit other classrooms, or to work with colleagues
(even in the same school), to set common curricular goals, to plan together,
or to discuss and plan examinations (Taylor, 19891. Teachers are assigned
to monitoring hallways between classes or dispensing drinking straws in the
cafeteria activities that can only leave them wondering why they were ever
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attracted to the profession of teaching. Although decision-makers are generally
aware of the extent to which working conditions undermine the professional
nature of teaching, they are often unable to change the policies. These policies
also convey a lack of understanding of the special role that science plays in a
student's education at all levels, as well as the special conditions needed for
successful instruction in science.
In addition to the nonprofessional burdens endured by teachers, other
aspects of the teaching environment impede effective education. The classroom
has become a microcosm of the myriad social and economic problems of
society. Teaching toward the goal of academic excellence is but one of the
many tasks that teachers are expected to perform. Schools are expected to
serve other purposes, such as socializing young people into their culture and
preparing students for specific occupations. But life experiences that students
bring into the classroom affect how receptive they are to learning. Teachers
are expected to help students overcome their nonschool problems. An endemic
culture of poverty in the inner cities of large urban centers perpetuates harmful
social activities. Moreover, peer pressure often discourages students from even
trying to succeed academically (Chubb, 1988~. A recent report of the Institute
of Medicine brought to light the prevalence of mental illness among our nation's
youth (Institute of Medicine, 19891. Inadequate pay provides little incentive
for teachers to stay in the teaching profession in the face of these and other
obstacles, such as overwork and the violence directed at teachers and students in
large urban areas. Teachers must also overcome the negative image of science
held by students and often by their parents.
Overcoming the barriers to effective education is often left to the teachers,
who are helpless to effect any major change, given the dynamics of a system
over which they have little control. Instead, they are forced to work within
a hierarchical system imposed by both school systems and teachers' unions.
One example involving salary will illustrate the point. Except for states with
a single, statewide salary schedule, each school district sets remuneration with
the usual provision that teachers will not be hired into the district at a salary
that recognizes more than 6 years of experience. Therefore, senior teachers
who leave a school district must take salary cuts to move. In effect, unlike
members of most university and business professions, public-school teachers
who have stayed in a school district (or state) for more than several years
become permanently indentured servants. The members of no other profession
are so hobbled.
If the goal of effective education is to be realized, teachers must be given
more control over the system in which they work.
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51
Recommendations
The following recommendations will expedite reform by increasing the
professionalism of teaching.
· Seriously addressing the need to teach science more effectively will
require changing some current administrative practices. More flexibility is
required in the scheduling of classroom and preparation time, in the pursuit
of related professional activities by teachers, and in teachers' sharing of
responsibilities.
This recommendation carries some inevitable fiscal implications, and
a word on that score is appropriate. Goals of "reform" are of two kinds.
The first merely specifies minimal accomplishments that can be effected
by policy changes or new rules. The second aims higher by attempting
to alter the result of the educational process in some fundamental way,
e.g., by maximizing the intellectual accomplishments of individual pupils.
Requiring more courses for graduation, lengthening the schoolday, and
inserting yet another normalized test are examples of the first. Although
they might seem to speak to the problem, by themselves they are merely
political palliatives that leave the impression that something important is
being done. In contrast, changing the outcome of schooling in a basic
way seriously disturbs the system and presents a challenge to virtually
every interest group on the scene teachers, administrators, and taxpayers
(Airasian, 1989~. True educational reform will be expensive and rock many
boats, and those who must pay for change should be clear about the goals
they wish to achieve.
· Obstacles to effective teaching must be lifted. Inasmuch as text-
books and testing play major roles in determining how biology is taught,
teachers must be encouraged to experiment with new techniques of peda-
gogy and assessment. School policies, rather than perpetuating isolation,
should be tailored to support and encourage teachers in working together in
developing ideas. School administrators can endorse activities for teachers
to share ideas about new curricular approaches through policies allowing
released time and "free" time during the school day. Teachers must also
be encouraged to exchange information about what works and what does
not work in the classroom-e.g., pedagogical techniques and laboratory ap-
proaches. School policies should encourage teachers to become involved in
new curricular projects and should assure them of long-term commitment
and support for successful innovative efforts.
· The nonteaching tasks assigned to teachers should decrease. Teach-
ers should be expected to devote nonteaching time to activities that will
enhance their ability to teach, such as laboratory preparation and tutoring
students. Valuable time should not be spent in monitoring hallways or
supervising lunchrooms.
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· School boards must be convinced that hiring experienced teachers,
who are paid more than less-experienced teachers, is sometimes best for
the children in the district. Market forces would then play a greater role in
public-school education. Districts that provided the best working conditions
for effective teaching would be able to attract the best teachers. Other
districts might have to improve working conditions and salaries, if they are
to retain or attract highly qualified teachers. Through such a change in the
conditions of teacher employment, both teachers and school boards would
have freer hands in creating faculties and working conditions that lead to
schools that communities would wish to support with enthusiasm.
Representative terms from entire chapter:
classroom practice
