Most people (even some scientists) feel like gagging whenever they see the phrase "Scientific Method". And yet, the Scientific Method (which we will call SM for short) is actually just a simple way to find out stuff. In this sense, we are all born scientists. The scientific community describes this process as a series of steps so that others can analyze and repeat what we have done. This series of steps is called the SM.
I will start with a simple example to show how the SM works. Say you are sitting at your desk and you try to turn your desk lamp on but it does not work. What is going on? Here are some possible explanations for this problem:
1. the lamp is not plugged
2. the bulb is burned out
3. the lamp is broken
4. a demon has put a curse on your lamp
5. something you haven't thought of yet
Which one should you choose to test first? Based on everyday experience, I bet most people in their right minds would choose either option 1 or 2. Why? Because they know something about desk lamps from past experience.
Okay, let's choose option #1 since
it is the easiest: oops! the lamp is already plugged in!
Okay, so we can throw away option #1 and go to the next easiest option,
#2, as our alternative explanation for why the lamp does not work (and
so on). As we go down the list, most people will naturally always
pick the options that are the EASIEST to
test! That is just common sense. Notice that this is a process
of elimination: if
a possible explanation fails the test we simply throw it away, no
tears shed, and move on to the next option. (Can you make mistakes?
Yep! More about that later.)
(Note: I don't know about you, but I think I would go to option #4 only after exhausting all possibilities with options 1-3. But option #4 is probably impossible to test ...i.e. demons are outside the scope of science... and I would have thrown the lamp away by that time anyway!)
Okay the trick now is to show how what we just did can be described as a method (the SM)! Here we go:
1. Identify a problem (for
example, lamp does not work)
2. List possible explanations (alternative hypotheses) based on your previous experience (what you already know); note: all of these hypotheses must be testable (no demons allowed!)
3. Pick the most likely hypothesis (or the easiest one to test); this is called the "rule of maximum parsimony" (for example, the bulb is burned out)
4. Make predictions based on the hypothesis: "if this hypothesis is true, then the lamp should work when I replace the bulb"
5. Test the hypothesis by determining if the prediction is true: make an observation or do an experiment (for example, replace the bulb)
6. Move on to test alternative hypotheses if your first one fails the test.
7. Repeat until you are convinced that you have identified the most likely hypothesis (publish!)
I mentioned earlier that you can make mistakes. This is because the SM, like anything else in life, is not perfect. All kinds of errors can be made along the way. For example, what if your initial information is incorrect? In this case you may pick the "wrong" hypothesis which could mean that you will waste a lot of time and/or money. This may not concern other people too much if your research is focused on, say, abdominal bristles in tropical gnats. However, the stakes could be very high if it is a potentially important medical or environmental problem, such as deformed amphibians. This is why a crucial part of scientific research is to find out what is already known about the problem.
Another common problem is that one may go chasing merrily down a particular path, getting lots of positive feedback in the way of results, and actually end up missing what is really going on. For example, I could hypothesize that the sun revolves around the earth, predicting that if this is true, then I should see the sun come up over the horizon on one side, watch it move across the sky, and disappear over the opposite horizon. My initial observations would support this hypothesis, and I would conclude that indeed, the sun revolves around the earth! It is only because scientists kept examining this problem from different perspectives, doubting one another (and even themselves) and using hypotheses to make predictions and then testing the predictions, that our understanding of how the solar system works gradually emerged.
Going back to our dysfunctional lamp, perhaps the bulb burned out because of a power surge. If it keeps happening, we will eventually get it (unless we are electronics-challenged), but if it was a one-time deal (e.g. a lightening storm), we may never find out what really happened!
This sort of thing really does happen all of the time, and it is the reason scientific work is called RE-search rather than just "search": we keep looking and looking and re-examining what has already been examined, trying to leave no stone unturned. However, we do have to decide to start somewhere, and that is where maximum parsimony (linked with past experience and knowledge) comes in. But no experienced scientist would stop there.
Scientists are never satisfied!