Chapter 1 Scientific method

The Process of Science

Hypothesis : an idea, or educated guess, that can be tested. It is often good to have several, alternative hypotheses.

Prediction : a logical consequence of a hypothesis.

Experiments are often designed to disprove the hypothesis.
This is because it is much easier to disprove a hypothesis than to "prove" it. A single experiment can show that an idea is wrong, but a thousand experiments do not prove that an idea is correct.
For example see: Scientific method

The experimental group differs from the control group usually in one variable eg testing new medications

Placebo : a pill or injection that contains no medication. Antidepressants and placebos.

Blind trials mean that the subject of the experiment does not know if they are in the experimental group or control group. A double-blind trial means both the subject and the technician do not know which group the subject is in. Drug companies use double-blind trials to test new medications.

Animal models, like rats and mice, can be used to test new drugs or conduct experiments.

Correlations, or relationships between two variables, can indicate a connection. For example, people with higher stress levels have more colds. (Fig 1.8). However correlation does not mean that stress actually causes the cold.

Sample size : the larger the sample, the more accurate the results.

Theory : a scientific theory has been supported by many experiments:
eg atomic theory, germ theory, and the theory of evolution.

Last edited March 2009, by David Byres, dbyres@fccj.edu