Wednesday, February 28, 2007

Scientific Method, Puzzles and Dinosaurs

One of the most misunderstood concepts in science is the scientific method, or “the process by which scientists, collectively and over time, endeavor to construct an accurate (that is, reliable, consistent and non-arbitrary) representation of the world.” The biggest misunderstanding is that it is only used by scientists. This is not the case.

The scientific method is simply a process by which questions are explored and their potential answers tested for validity. There are few restrictions for what these questions can be, as long as they focus on acquiring new understandings of the world through their answers.

Let’s look at the simple example of a jigsaw puzzle, illustrated here:

I use [a jigsaw] puzzle as an example of how science works. I use those cheap 100 piece kid puzzles that you can buy at WalMart, [which have] an identical cut out pattern with different pictures.

The first thing that we do is turn over the pieces and I try and get the students to think about the problem. Just looking at the pieces, can they come to some sort of idea of what the picture is? Unless you have some type of super genius that can assemble the pieces in their mind the students can only come up with vague ideas of what the picture might be. We do this in science all the time. Even the assumption that it will make a picture that they can make sense of should be pointed out to them. Try and get them to think about what they are doing.

When they start to assemble the puzzle ask them what they are doing. None of the students I've had have tried the random assembly of just putting any two pieces together. Get them to understand that they are hypothesis testing by grouping the pieces by whatever character that they are using (color, pattern, shape). Ask them why their hypotheses fail so often. Get them to understand the problem that science deals with when you make assumptions based in incomplete data. If they were able to take all the characteristics of each piece and make a perfect analysis they would never be wrong in their choice of which pieces fit where, but using the mark I eyeball and only a limited set of characters you often make mistakes. You have to expect to be wrong quite often in science. You have to be able to test your hypotheses.

Completing a puzzle surprisingly involves myriad questions and gives further insight into this logical process, as I will expand upon below.

Let’s say we come across a pile of cardboard pieces on a table. With no one nearby to inquire with, we start to wonder what exactly the pieces are doing there. The first question we ask might be, “What are these colorful shapes used for?” Here, we are performing the first steps of the scientific method, by OBSERVING the surroundings (noticing that there are cardboard pieces on an unattended table), and by IDENTIFYING a question we want to answer.

What could a pile of shapes, colors and patterns possibly be doing on the table? How could we go about answering this? For many of us, our childhood memories are interspersed with jigsaw puzzles filling a problem-solving niche in our early development. Past experiences with puzzles give us an idea for the purpose of curvy, colorful cardboard pieces: they might be interlocking parts of a larger picture.

Using a priori knowledge like this is one method of HYPOTHESIS FORMULATION, the next step in the scientific method. One may use past experiences, induction, or a little ingenuity to come up with hypotheses, since a hypothesis is simply one possible answer to a problem. And there are always more we can consider.

What other hypotheses can we come up with? Perhaps these pieces are the leftovers of an arts-and-crafts project. Perhaps they are excrements of mutant termites. Perhaps they were left by a hostile species of aliens as target coordinates for an impending onslaught of nuclear weaponry. We seem to be approaching the limits of absurdity as we go on, but these ideas can still be considered. Let’s stick with the first and most likely guess: they are puzzle pieces.

Our next step is to PREDICT what should happen if our hypothesis is true. If these pieces are indeed parts of a puzzle, they should then fit together in a logical pattern of colors to form a picture.

The most fun is had by scientists in the following phase: EXPERIMENTATION. Despite any stigmas attached to the word, one does not need to be working with radioactive carcinogens distilled from puppy blood for it to be called an experiment; an experiment is purely a way to determine if test results support predictions. In this case, an experiment would merely be taking two pieces and fitting them together. Any child old enough to play with puzzles can, by definition, perform experiments.

Picking up the first two pieces we see and attempting to fit them together might not work. That is, through our experiment we find that our results do not support our predictions. It happens. In science, it happens quite frequently. Hypothesis testing invariably involves many failures before success. If two pieces do not fit together, we try again with other pieces.

We continue to fit together pieces and after a few correct connections, we ask ourselves why we are successful at times and not at others. We recognize that we are not just picking up random pieces and experimenting, but instead we are using some logic during successful experiments. Through testing our initial hypothesis that these pieces of cardboard make up a jigsaw puzzle, we actually formulate a new subset of hypotheses: “These two pieces will fit together because….” They could fit together because they have the same color, or the same pattern, or the same shape, or any other type of similarity. Logic tells us that two interlocking pieces will look somewhat the same, and so we experiment by picking up two pieces with similar traits (color, pattern, or shape, depending on our hypothesis) and determining if they connect.

After each experiment, successful or not, we advance to the last step of the scientific method, or REVISION & REPETITION:

Let’s say that we begin our experimentation by picking up two random pieces and attempting to fit them together. Failure is afoot and the pieces do not fit together although we predicted they should. We then reexamine our hypothesis, that these pieces are part of a jigsaw puzzle. Through this last step of the scientific method, we determine if our hypothesis can be revised to fit experimental results. Seeing as how there are many pieces, it is possible that we simply did not pick up neighboring pieces, and so our hypothesis is still valid. We can repeat the experiment with different pieces and continue the thought process, hoping to find pieces that are neighbors and therefore that link together.

Revision takes place through making the hypothesis more precise—that is, by including the idea of similar characteristics for neighboring, interlocking pieces. We attempt to repeat experiments by looking for pieces with matching colors. If we were to still encounter failure, we could continue with matching colors to link pieces and hope repetition nets us eventual success, or we could further revise our hypothesis and instead experiment with pieces of matching shapes, perhaps by looking for pieces that have a straight edge on one side. The process continues. After successfully matching all pieces with their interlocking neighbors, we see a beautiful picture of the Aurora Borealis, and have proven that our hypothesis is correct.

The steps we’ve taken to answer the question about the unknown cardboard cutouts — Observation, Identification, Hypothesis Formulation, Prediction, Experimentation, and Revision & Repetition — all form the foundation for the scientific method.

Let’s now briefly jump from jigsaw puzzles to another non-sciencey example:

Cyanide and Happiness, a daily webcomic
(Cyanide & Happiness @

Assume that this comic detailed a hypothesis for why dinosaurs became extinct: God threw rocks at them, shouting “oh shit oh shit oh shit”.

While hypotheses are only guesses to the riddles of life, there is a distinction between good and bad guesses. One of these distinctions refers to FALSIFIABILITY, or the capacity to eliminate plausible alternatives. A good guess is completely at the mercy of the scientific method, meaning it allows for experimentation and is subject to being disproved and revised. Our initial hypothesis related to our puzzle is falsifiable: for example, if we were unable to form a picture with our potential puzzle pieces, we would eliminate the possibility that we have a single picture made up of interlocking pieces; they might actually be pieces from more than one puzzle, or perhaps they are not puzzle pieces at all.

Any hypothesis involving religion or god, by nature of logic and methodology, is a bad one. One cannot prove or disprove god just as one cannot prove or disprove god’s aversion to reptiles. There is no way we can logically carry out such an experiment to test this guess, and thus we can never hope to revise it for the better, other than eliminating it completely. Our time is better spent not even making this guess since it will never be more than a random, illogical thought with no basis for truth.

We have now gone over two common items, puzzles and comics, in examining the usefulness of the scientific method. Consider how you approach and solve other problems in your daily lives, and see how closely your approach mirrors the steps outlined here.

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