it's the real thing - the scientific method

let students explore the open-ended nature of scientific research.

The scientific method is describe in the first chapter of almost every science textbook. We, dutiful teachers, instruct our students to follow this time-honored method when they embark on individual research projects -- inadvertently implying that scientists follow a nice, neat, simple recipe and that if students do the same, they are guaranteed success in their chosen projects.

Take a look at the classic series of instruction:

The Scientific Method

1) pose a problem

2) state a hypothesis

3) test that hypothesis by designing a laboratory experiment in which all the variables are controlled, except for the one being tested

4) observe and record information

5) analyze the data

6) draw conclusions

7) accept or reject the hypothesis.

Is this the method of Darwin, Einstein, Edison, Hubble or Fossey ? True, it can be argued that their research "fits" the scientific method, but it's difficult to imagine these famous scientists simply following a recipe like the one state above. We are limiting students and ourselves when we strictly adhere to the scientific method.

Einstein defined research as "The search for those highly universal laws from which a picture of the world can be obtained by pure deduction. There is no logical path leading to these --- laws. They can only be reached by intuition, based upon something like an intellectual love of the objects of the experience."

Does this sound like the narrow definition of the way scientists work that we've been teaching our students ? Could a scientists who said, "We should make things as simple as possible but not simpler," condone such instruction ?

it's a trap

We teach students to approach a problem by way of an algorithm in the form of the scientific method. We relate numerous, neat examples from the history of science. Then one day we simply tell our students to go out and "do science," having limited them to a rigid concepts of what that means. This naturally frustrates students. In return, we hear, year after year, such statements as, "I can't think of a research question." "Tell me what to do and I'll do it." "I want to make a model of a heart or radio or volcano --- and so on --- and explain how it works."

One way to free students from feeling trapped by the scientific method is to encourage them to examine problems from new vantage points. The Cokes Float activity lets teachers show students that they can approach a research problem uninhibitedly.

Put Coke Classic, and a Caffeine-free Diet Coke, into a container of water. In most cases, the Coke Classic sinks and the Diet floats.

I have not found this -- I find regular coke floats --- and diet coke floats even higher. Supposedly - regular Coke has less sugar than regular Pepsi ( which sinks ).

Test all the cans first - so you can lead the students to a desired conclusion. For example - you can give them diets that float and non-diets that sink.
THEN - zing their brains with the non-diet Coke which floats !
Oooops - they have to change their idea. THAT'S science.

Giving them some non-diets that sink and others that float may be too many variables to handle at one time and the brain's RAS system shuts down. The author of this article did not "sort" the cans first because of her goal dealt with the scientific method. Note her last paragraph.

Note: Coke Classic sinks according to the author - and Caffeine-free Diet Coke floats. Is that due to the "diet" variable or the "caffeine-free" variable ? That might be too much for the kids to decide.

Ask students to list their reasons why this phenomena occurs. They can use their hypotheses to help them develop a method of testing later. Brainstormed hypotheses are based on the students' prior knowledge of sodas, sinking and floating, and mass-volume relationships. Typical responses include:

• manufacturing error - one can has more soda

• the caffeine makes the difference

• caffeine-free is less dense than regular coke

• regular cokes is less carbonated

• red paint (color of can) has more mass than gold paint

• one can has more mass than the other

• sugar has more mass than the Nutrasweet.

Instruct students to think of a hypothesis and design a procedure to test it. Discuss reasoning techniques so students can distinguish between inductive thinking and deductive thinking

inductive:

information from specific leads to a general conclusion

deductive: reasoning from the general to the specific.

The bridge between inductive and deductive thinking in hypothesis formation comes by pulling all the facts together and asking, "What if . . . ?"

Collect the students' designs for testing their hypothesis. Evaluate the students' understanding of the relationship between hypothesis and procedure. If you find faulty logic, or if you wish to help your students see the processes of good hypothesis formulation, ask them to write down the reasoning behind their hypotheses. Ask yourself these questions as you evaluate their procedures. Did the students use their hypotheses as a guide for writing their procedure? Do the procedures actually test the hypotheses as stated ? Can the students actually conduct the experiments and draw appropriate conclusions ?

Once the procedures are evaluated, allow the class to conduct their experiments.

There can be only three acceptable conclusions -

• the data support,

• the data reject, or

• the data are inclusive to support or reject the hypothesis.

what's the deal ?

You probably hypothesized that the actual cause of Diet coke floating in is the difference in density of the two liquids due to the difference in the mass of the sugar and Nutrasweet. Three classes participating in this activity discovered that 30% of the regular cokes floated. One class decide that there must be an error in manufacturing and ignored the Coke Classics. The two other classes continued with their hypothesis testing.

Through their own experimentation, those children discovered that the Coke Classics that did not sink contained less than the advertised 12 oz. They followed up their research with class to the local bottling company which led to an interesting dialogue. How different the results would have been if the teacher had set up the experiment with cans chosen after testing them to make sure that all the cans did what they were "supposed" to do.

We teachers must emphasize that there are many methods for finding solution in science. We must help the students direct their natural curiosity toward open investigations. It is important to have rules -- rules that are allow us to compare our observations with others. Following widely-agreed upon conventions provides an important understanding when we write and talk about those observations. We investigate by these rules, but they often only useful constraints, not unyielding control of the investigation.

Talk with your students about how some real-life, famous experiments progressed. Let them emulate the various inventive and certainly individualistic approaches Einstein, Pasteur and other took. Free your class from the confines of rigidly structure "method."