Unit H1


For many people, scientists are mysterious figures with a deep knowledge that ordinary people cannot understand. They are thus regarded with the same awe tinged with mistrust that in former times was reserved for the sorcerers and holders of magical powers. It is true that a scientist must learn many facts and even the scientific language used in his specialty. The facts are the accumulated knowledge of many generations of scientific work, and the language or terminology allows him to communicate with other specialists around the world. However the scientific method is basically very simple, being more a way of thinking about problems and their solution.

While the knowledge and language of science are useful, they are not always necessary for scientific solutions to local environmental problems. They can be replaced by long experience in a place and good powers of observation. Most local languages have names for the plants, animals, places and other parts of the environment; while it may be difficult to use them to communicate outside the community or language group, they may be perfectly adequate for local use. It should thus be possible for someone like you with reasonable intelligence, good powers of observation, and an understanding of the scientific method, to become a kind of local expert or scientist able to do research and find solutions to local problems.

Research means to study something carefully in order to learn something new about it. The scientific method is a way of doing research. It usually involves several steps which will be explained below:
- definition of the problem,
- looking for explanations or solutions, and
- measuring and experimenting.

It is often necessary to go through this process several times, as the results one set of experiments or observations may raise new questions or suggest other explanations. Also, one of the proofs of successful science is that others should be able to repeat the same experiments and to get the same results.

Definition of the problem

Defining what the problem is in a way that it can be studied scientifically is perhaps the hardest step in the process. Sometimes people know that something is wrong, but they cannot think about it very clearly. Often they are so used to the way things are that it never occurs to them to think about them or to look for ways to change them. Recognizing the possibility of change or improvement is the most creative step in the scientific method.

For example, suppose people have always climbed a mountain by a particular path. Most would never stop to think that there might be another way up the mountain. Asking the question "Is there a better way up the mountain?" is the first step in the scientific method.

Problems can be defined in different ways, perhaps best illustrated by different types of questions.

They can be problems of description:
- What is there?
- What is it made of or how is it made?

They can concern a process or cause and effect:
- Why has that happened?
- How does it work?

They can raise questions of time or place:
- What was that like before?
- What will it be like?
- Where did it come from or go to?
- Is it the same here as there?

They can be problems of human activity or control:
- What can be done to change that?
- How can we keep that from happening?
- Is there a better way to do it?
- If I do this, what will happen?
- How can we get more, or do it more easily?

Almost any problem can be put in the form of a question. However, if a problem or question is too general, it will be impossible to use the scientific method to solve it. The more specific you can make a problem, the better the chance of finding a solution.

For instance, suppose you are a fisherman. You could ask "How can I catch more fish?", but this will not be very helpful. If you ask "How can I catch more fish with my trap?, you have already focused on a specific case where you could consider the form of the trap, the materials it is made of, the bait used, the location and time for setting it, etc. An even more specific question, such as "What kind of bait will attract the most fish to my trap?" will make the search for a solution or improvement that much easier.

Looking for explanations or solutions

Once you have defined your problem as specifically as possible, it is normal to think about what the solution might be. Often we can imagine different possibilities or explanations based on what we already know about the problem. For instance, in the example of the path up the mountain, we may already have an idea of other routes that could be tried. As we think about the problem, we may see that there is a choice between two or more solutions which at first glance seem equally good.

We also must define very clearly what our criteria are for judging what is a good or bad solution. A good path up the mountain for a man on foot may not be good for a horse, and even less so for a road for cars and trucks. The man may prefer a short steep path, where a car could get there faster on a long gently sloping route.

Our way of thinking about problems and explaining them depends on our background and education. Different cultures have their own sets of values and ways of explaining natural phenomena. Even in science, schools of thought vary from one country to another, and it is not possible to say one is necessarily better than another. For instance, Chinese medicine is very different from French medicine or American medicine, yet each succeeds in curing many illnesses, and each can be enriched by learning from the experience of the other. This is an area that is closely tied to culture, language, and religion, among other fields that are beyond the scope of this training programme. For our purposes, what is important is that you think through clearly and carefully what the solutions or explanations might be in your own cultural context, so that you know what you are trying to test with the scientific method.

Again, the more specific you are in your proposed solutions or explanations, the better the chances of proving them right or wrong.

Measuring and experimenting

Once you know precisely what you want to test, you can make measurements or experiments to prove or disprove your explanation or to establish the best choice. An experiment is a test or trial to find out how something works or to see what happens. Often it means doing something on a small scale or in a simplified way in order to answer your question. For some kinds of problems, the answer can come from making certain measurements or observations. For example, in the case of different paths up the mountain, after having looked at the mountain from a distance or on a map to see what routes might be practical (your possible solutions), you might then test each possible route by walking up it, to see if there is not some hidden obstacle, and to judge if it might be easier or faster than the present route. Or having thought over the different possible baits for your fish trap, you would then experiment by trying each one several times to see which was the most successful in attracting fish.

The design of a good experiment is not always as easy as it seems. There should be only one possible cause of the result of an experiment, that will either prove or disprove your explanation. If more than one interpretation is possible, then your question will not be answered (except perhaps by another experiment).

It is most important in an experiment to change only the one thing you want to test. Everything else should stay the same. This will require great care in conducting your experiments. For instance, suppose you are testing baits in your fish trap. If you put one kind of bait in one trap, and another in another trap, you must be sure that the traps are exactly the same, and are in exactly the same kind of place, or the difference in catch could be from the kind of bait or the kind of trap or the location of the trap. If you decide to put the different baits in the same trap on different nights, you must be sure that there is no difference between the nights (moon-lit or cloudy, high or low tide, windy or calm, etc.) or these other factors might be the cause of the difference and your experiment will not prove anything.

Often it is necessary to do an experiment and a control. A control should be just like the experiment, but without changing the thing you want to test. If a doctor wants to test a medicine, he may take two groups of similar people, and give the medicine to one group while the other group (the control) gets similar looking pills without the medicine. No one (often not even the doctor) will know which is which until after the test. This is because people often get well just because they think they are taking a good medicine, and even the doctor might unconsciously judge the results differently if he knew which patients were taking the real medicine. The control group makes it possible to prove that the medicine made a real difference.

In the same way, you might need to set up two sets of fish traps. In one set (the control) you would put a bait which you know will catch a certain number of fish. In the other (the experiment) you would put the new bait to be tested. You could then say whether under that set of conditions the new bait attracted more or less fish than the other.

Another problem with experiments is the number of times an experiment is done. Many things change just by chance. The same fish traps with the same bait will not always catch the same number of fish. To prove that an experiment worked, the difference must be more than what might be caused by chance. Scientists use complicated methods with statistics (a kind of mathematics) to calculate if the result of an experiment is within the range of what might happen by chance, or is sufficiently different that the probability is high that it was caused by the experimental change. What is important to remember is that the more times an experiment is done, the greater the probability that a difference between the experimental and control group is significant. Also, the larger the number of experiments, the smaller is the difference that can be detected. You will probably not be able to check your results for statistical significance, but you should do an experiment enough times to be reasonably sure of the result.

One important proof in science is repeatability. Anyone anywhere should be able to do the experiment under the same conditions and get the same result. If you (or someone else) cannot repeat your experiment, there may have been some hidden variable that was not controlled. You will need to try to find what it was and then plan your experiment more carefully.

An experiment is often a way of trying something out on a small scale to see what it does or if it works before investing time and effort in a full scale use. You experiment with a new bait on a small scale before using it in all your fish traps. Be careful that nothing changes between your small scale experiment and full scale use. Sometimes the increase in scale itself can create new problems. Suppose your new bait works well in a small experimental trial, but when used in larger quantities it attracts too many sharks who damage the fish traps. A new crop may grow well in a trial, but when planted on a large scale it may be easily attacked by some pest. It may be necessary to make first a small experiment, then a larger one, and finally a full-scale trial to prove that the change is worthwhile.

People in rural areas are very conservative in the way they do things because the old ways have proven themselves over many years and the proposed changes are largely untested. An experiment or trial can show them that a change is good at the same time that it may show how to adapt the change to local conditions.

Importance of careful observation

This unit has described the essential principles of the scientific method: defining a problem, looking for explanations or solutions, and testing those solutions with carefully controlled experiments. There is a skill that is fundamental to success in the use of the scientific method, and that is the power of careful observation. A scientist must learn to look carefully at the world around him, whether it be to identify problems, look for solutions, or to follow and record the results of experiments. Much of the training of a scientist involves teaching him or her to observe, and providing the knowledge to understand and interpret the results.

Many of you who have grown up in rural areas or small islands may have learned to observe the world around you quite naturally, because rural island life has always depended on an understanding of the environment. If you already have that skill, it will be easy to use it to apply the scientific method in your own local context. The exercises accompanying this unit can also help to develop your skills as an observer.


It is easier to understand the scientific approach to a problem through specific examples, a few of which are developed below.

The problem of the best path up the mountain has already been mentioned. In many places the same routes have been used for centuries, and follow paths first traced by animals or people travelling on foot. Today the destinations, means of transportation and methods of construction have all changed, and the old route may no longer be the best. The first step is recognizing the need to look for a new route (the problem). The criteria for a good route are then defined (distance, slope, ease of construction, etc.) and one or more alternatives are identified. The question to be tested is "Which is the best route?" The test would involve measuring the different routes for distance and slope, examining the rock and soil along the route for problems of construction, etc., to provide the information on which a choice can be made. In this case the old path is the control against which the alternatives are compared.

The problem of improving the catch in fish traps has also be mentioned. A test of fish traps might look into their form, the materials of which they are made, their location, the timing of their placement and retrieval, and the bait used. We can select just this last item and ask what is the best bait to use for catching a particular fish. There may already be a traditional bait, but many new things are now available that did not exist in former times, so why not see if any of them are better. Different possible baits could be selected on the basis of colour, form, odour, texture, cost, availability, etc., and some trials prepared in which perhaps 5 traps are baited with the traditional bait and 5 with a new bait (depending on the number of traps available). The traps, carefully marked as to type of bait, are all placed in similar areas, and the total catch with each bait is compared. If a new bait looks promising, it can then be tried on a larger scale or in different situations, leading possibly to its adoption as a replacement for the traditional bait.

Consider as another type of problem a field of taro that has been damaged in a cyclone or storm. To define the problem we must ask what precisely caused the damage. This will require listing all the possible causes or explanations: wind damage, plants buried in silt or drowned by flooding, soil washed away, salt carried in from the sea, etc. We should then examine the field carefully for evidence to support one or another of our possible explanations. Once we have found the real cause of the damage, we can ask how it can be prevented the next time. This may require trials of different types of windbreaks, flood controls or drainage before one is finally adopted. If it helps to protect the taro from the next storm, some progress will have been made in the community.

The scientific method is not so new in most traditional societies. People have always tried new things out, and kept what seemed to work. A scientist simply does this more consciously and systematically. In pre-European New Caledonia, the "Master of the Yams" had a small sacred garden near his house where he performed different rites associated with growing yams. These gardens may have served as small experimental gardens where he could observe the condition and development of the crop, and make recommendations accordingly to the people of the village. The method is similar to that used by modern agricultural scientists.


What is the first step in the scientific method?

How do you find an explanation or possible solution for a problem?

What are different ways of proving an explanation true or false?

How do you design an experiment?

What is a control?

What does it mean if you repeat an experiment and do not get the same result?

Can you think of examples of people who may have used the scientific method without realizing it?

How do you think traditional knowledge of the environment was discovered?

Are scientists the only ones who can use the scientific method?

What are the advantages of the scientific method over simple trial and error?

Instructions for trainers in the use of this unit

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UN System-Wide Earthwatch Coordination, UNEP, Geneva
Updated 7 April 1998