to Enquiry involve the student in activities that enable him or her to follow and participate in the reasoning related to a front‑ line item of investigation or to a methodological problem in biology. We present Invitations to Enquiry as the model of teaching drawn from the BSCS materials. Preparing to write this chapter, we obtained contemporary BSCS material and are pleased that it continues the spirit of scientific inquiry that drove the original model of cur‑
riculum and instruction. Reading the “Blue” version of the introductory high school course in biology (Greenberg, 2006), we learned a good deal, some updating our knowledge of science and some opening up topics and inquiries that were not in our undergraduate or graduate education programs. The basic text includes about 100 pages of studies for the students to use to con‑
duct their inquiries. The text relentlessly opens up ways of thinking about the collection and organization of information and the generation and testing of explanatory theories.
| I nvitations to enquiry
Credited to Schwab, this strategy was designed
to show students how knowledge arises from the interpretation of data to show students that the interpretation of data— indeed, even the search for data—
proceeds on the basis of concepts and assumptions that change as our knowl‑
edge grows . . . to show students that as these principles and concepts change, knowledge changes too . . . to show students that though knowledge changes,
Chapter Four Scientific Inquiry 81 it changes for a good reason— because we know better and more than we knew
before. The converse of this point also needs stress: The possibility that present knowledge may be revised in the future does not mean that present knowledge is false. Present knowledge is science based on the best‑ tested facts and con‑
cepts we presently possess. It is the most reliable, rational knowledge of which man is capable. (Schwab, 1965, p. 46)
Each Invitation to Enquiry (or lesson) is a case study illustrating either a major concept or a method of the discipline. Each invitation “poses example after example of the process itself [and] engages the participation of the student in the process” (Schwab, 1965, p. 47).
In each case a real‑ life scientific study is described. However, omissions, blanks, or curiosities are left uninvestigated, which the student is invited to fill:
“This omission may be the plan of an experiment, or a way to control one fac‑
tor in an experiment. It may be the conclusion to be drawn from given data. It may be an hypothesis to account for data given” (Schwab, 1965, p. 46). In other words, the format of the invitation ensures that the student sees biologi‑
cal inquiry in action and is involved in it, because he or she has to perform the missing experiment or draw the omitted conclusion.
The sets of invitations are sequenced to lead the students to successively more sophisticated concepts. And the nature of investigation is relentless.
Even in the first group of Invitations to Enquiry, the focus is topics related to methodology— the role and nature of general knowledge, data, experiment, control, hypothesis, and problems in scientific investigation. The subjects and topics of the invitations in Group 1 appear in Table 4.1.
Take a look at how the content and processes of Invitation 3 in Group 1 lead students to deal with the problem of misinterpretation of data.
Invitation 3
Subject: Seed Germination Topic: Misinterpretation of Data
It is one thing to take a calculated risk in interpreting data. It is another thing to propose an interpretation for which there is no evidence— whether based on misreading of the available data or indifference to evidence. The material in this Invitation is intended to illustrate one of the most obvious misinterpretations. It also introduces the role of a clearly formulated problem in controlling interpretation of the data from experiments to which the prob‑
lem leads.
To the student: (a) An investigator was interested in the conditions under which seeds would best germinate. He placed several grains of corn on moist blotting paper in each of two glass dishes. He then placed one of these dishes in a room from which light was excluded. The other was placed in a well‑ lighted room.
Both rooms were kept at the same temperature. After four days the investigator examined the grains. He found that all the seeds in both dishes had germinated.
Invitation Subject Topic
1 The cell nucleus Interpretation of simple data
2 The cell nucleus Interpretation of variable data
3 Seed germination Misinterpretation of data
4 Plant physiology Interpretation of complex data
Interim Summary 1, Knowledge and Data
5 Measurement in general Systematic and random error
6 Plant nutrition Planning of experiment
7 Plant nutrition Control of experiment
8 Predator‑ prey; natural populations “ Second‑ best” data
9 Population growth The problem of sampling
10 Environment and disease The idea of hypothesis 11 Light and plant growth Construction of hypotheses 12 Vitamin deficiency “If . . . , then . . .” analysis
13 Natural selection Practice in hypothesis
Interim Summary 2, The Role of Hypothesis
14 Auxins and plant movement Hypothesis; interpretation of abnormality
15 Neurohormones of the heart Origin of scientific problems 16 Discovery of penicillin Accident in inquiry
16A Discovery of anaphylaxis Accident in inquiry
Source: Joseph J. Schwab, supervisor, BSCS, Biology Teachers’ Handbook (New York: John Wiley & Sons, Inc., 1965), p. 52. By permission of the Biological Sciences Curriculum Study.
Invitations to enquiry, Group 1, Simple Inquiry: The role and nature
of General Knowledge, Data, experiment, control, Hypothesis, and Problems in Scientific Investigation
TaBle
4.1
What interpretation would you make of the data from this experiment? Do not include facts that you may have obtained elsewhere, but restrict your inter‑
pretation to those from this experiment alone.
Of course the experiment is designed to test the light factor. The Invitation is intended, however, to give the students a chance to say that the experiment suggests that moisture is necessary for the sprouting of grains. Others may say it shows that a warm temperature is necessary. If such suggestions do not arise, introduce one as a possibility. Do so with an attitude that will encourage the expression of unwarranted interpretation, if such exists among the students.
Chapter Four Scientific Inquiry 83 If such an interpretation is forthcoming, you can suggest its weakness by ask‑
ing the students if the data suggest that corn grains require a glass dish in order to germinate. Probably none of your students will accept this. You should have little difficulty in showing them that the data some of them thought were evidence for the necessity of moisture or warmth are no different from the data available about glass dishes. In neither case are the data evidence for such a conclusion.
To the student: (b) What factor was clearly different in the surroundings of the two dishes? In view of your answer, remembering that this was a deliberately planned experiment, state as precisely as you can the specific problem that led to this particular plan of experiment.
If it has not come out long before this, it should be apparent now that the experiment was designed to test the necessity of light as a factor in germination.
As to the statement of the problem, the Invitation began with a very general ques‑
tion: “Under what conditions do seeds germinate best?” This is not the most use‑
ful way to state a problem for scientific inquiry, because it does not indicate where and how to look for an answer. Only when the “question” is made specific enough to suggest what data are needed to answer it does it become an immedi‑
ately useful scientific problem. For example, “Will seeds germinate better with or without light?” is a question pointing clearly to what data are required. A com‑
parison of germination in the light with germination in the dark is needed. So we can say that a general “wonderment” is converted into an immediately useful problem when the question is made sufficiently specific to suggest an experiment to be performed or specific data to be sought. We do not mean to suggest that general “wonderments” are bad. On the contrary, they are indispensable. The point is only that they must lead to something else— a solvable problem.
To the student: (c) In view of the problem you have stated, look at the data again. What interpretation are we led to?
It should now be clear that the evidence indicates that light is not neces‑
sary for the germination of some seeds. You may wish to point out that light is necessary for some other seeds [for example, Grand Rapids Lettuce] and may inhibit the germination of others [for example, some varieties of onion].
Note: This Invitation continues to deal with the ideas of data, evidence, and interpretation. It also touches on the new point dealt with under para‑
graph (b), the idea of a problem. It exemplifies the fact that general curiosity must be converted into a specific problem.
It also indicates that the problem posed in an inquiry has more than one function. First, it leads to the design of the experiment. It converts a wonder into a plan of attack. It also guides us in interpreting data. This is indicated in (c), where it is so much easier to make a sound interpretation than it is in (a), where we are proceeding without a clear idea of what problem led to the par‑
ticular body of data being dealt with.
If your students have found this Invitation easy or especially stimulating, you may wish to carry the discussion further and anticipate to some extent the topic of Invitation 6 [planning an experiment]. (Schwab, 1965, pp. 57– 58)
The format of this investigation exemplifies the BSCS mode. The students are introduced to the problem the biologist is attacking, and they are given some information about the investigations that have been carried out. The students are then led to interpret the data and to deal with the problems of warranted and unwarranted interpretations. Next, the students are led to try to design experiments that would test the factor with less likelihood of data mis‑
interpretation. This syntax— to pose a problem about a certain kind of investi‑
gation, and then to induce students to attempt to generate ways of inquiring that will eliminate the particular difficulty in the area— is used throughout the program.
The course proceeds in the inquiry manner. In one invitation the focus is on how we can infer the function of a given part from its observable charac‑
teristics (i.e., what is the evidence of function?). In this model, the question is not posed directly. Rather, the student is guided through an area of investiga‑
tion, which in this invitation has been framed to embed the methodological concern and the spirit of inquiry. Questions are then posed so that the student himself or herself identifies the difficulty and later speculates on the ways to resolve it.
And the issues surrounding the nature of inferences are surfaced. Schwab notes that during the investigation it is reasonable to conjecture that
Motion, attachment, and shape taken together suggest that muscles in general move one or all of the other parts of the body to which they may be attached.
Such inferences about function are only probable. But so are practically all inferences in science. In later queries, we shall make a point of the doubtful character of functional inference. (Schwab, 1965, pp. 174– 176)
The course continues in this vein.