This is how the scientific community objectively acquires new knowledge. You can use it to question your beliefs and theories.
Modern technologies are expanding our knowledge and improving our lives faster than any time in history. As a result, we are continually barraged with new claims and ideas. A typical example is that not too long ago nutritionists agreed the way to good health was to remove fat from our diet. Now they are saying if we want to stay healthy fat is okay, and it's the sugars that should be reduced. Both sides of the argument make sense, but how do we decide which plan to follow?
People have a tendency to follow their intuition.
Interestingly enough, people have a tendency to believe what they feel comfortable with, and whether the concept is technical or simple, they generally judge new ideas the same way. Recent studies have shown that most people, even highly educated persons, have been told only what to think, not how to think. Half of college graduates believe in concepts like magnetic therapy and ESP. They accept ideas that blend with what they have learned, and rationalize the rest away. The result is that most of us don't necessarily draw reasonable conclusions from the available evidence, but give more weight to what we intuitively believe.
A logical tool for decision-making
Even for college graduates, there is a logical tool which allows them to cut through the confusion. Scientists have used what has become known as "The Scientific Method" to overcome personal, professional, and social bias since it was first proposed by Roger Bacon in the 13th century. Another name for the scientific method is "Evidential Reasoning" and anyone can use it to separate reasonable ideas from those that are questionable.
This is how it works in five steps:
1) Observe – Examine the evidence and formulate a question. Take measurements of any variables. You must choose a question that has a quantifiable answer. (e.g. "Why do I continue to gain weight?") Weigh yourself and measure your waist size.
2) Hypothesize – Formulate a possible explanation which describes the observation. "I'm eating the wrong foods or it could be because I'm not exercising. One of those bad habits are the reasons I continue to gain weight."
3) Predict -Make a prediction based on the hypothesis. "If I follow a reduced carbohydrate – high fat diet or start walking regularly, I should stop gaining weight." The prediction must be falsifiable, that is, it must be possible to conceive of evidence that can prove the hypothesis false. There is the possibility that the diet or exercise may cause weight gain.
4) Experiment – Test and validate the hypothesis by experimenting. Follow a new diet regimen for a month.
5) Evaluate – Analyze the results of the experiment. Weigh and measure yourself after 30 days. If your hypothesis proves to be correct, you've lost weight and can now fit into your favorite jeans, make another prediction to test your theory (like exercising, but not dieting). If you continue to gain weight, make another informed guess. Perhaps exercise and the diet will help you control your waist.
Two fundamental rules
There are two fundamental rules accompanying a well-designed study that must be followed: 1) Every hypothesis must be falsifiable. If a claim can't be proven false it cannot be proven to be true, and 2) Experiments must be repeatable. The experiment which proves a hypothesis must be repeatable by other researchers. Not following these rules are the usual reasons pseudo-scientific claims like magnetic therapy and numerology are not accepted by well-informed people.
Observations can be difficult to measure (e.g. the consequence of an astrological reading) and some types of experiments are hard to control (e.g. patient compliance for an experimental diet), but one can use evidential reasoning to test the validity of just about any claim if there is enough information about how the "researchers" arrived at their conclusions.