I n t r o d u c t o r y   M a t e r i a l :     L e c t u r e  # 2 Vocabulary | Study Questions
The Scientific Method
Objectives:
  1. Understand the scientific method and its significance.
  2. Recognize the role of the scientific method in the biological sciences, in the global society, and in your own life.
  1. The scientific method: a systematic approach for accumulating data and testing the validity of hypotheses
    A rigorous procedure that follows a standard format (is not haphazard).
    1. Observations
      We begin with observations, and the desire to understand them (e.g. plants growing where there is sunlight).
    2. Ideas
      We formulate ideas about the observations: possible explanations (e.g. maybe plants need light to grow).
    3. Hypothesis
      From the ideas we gather, we develop a testable hypothesis. or 'best guess' (e.g. If plants need light to grow, then plants will not grow in the dark).
    4. Testing of hypothesis
      We formulate an experiment that will test the hypothesis. (e.g. Set up two similar groups of plants; put one in sunlight and keep the other in the dark, (all other factors constant, such as water). The experiment must be set up so that:
      1. Evidence must verify that only the experimental variable is responsible for any observed changes.
        The experimental variable (e.g. sunlight) is the variable that differs between the experimental group and the control group. In an experimental group, the experimental variable is manipulated and results observed. In a control group, the experimental variable remains constant, and results observed as a standard of comparison to measure the experimental results.
      2. Results must be reproducible
        If the results of an experiment cannot be consistently reproduced, they will remain in question (e.g. cold fusion).

        3. The independent variable is the experimental variable: the one we are testing (e.g. light). The dependent variable is used to evaluate the experimental variable (e.g. plant response).figure 2.1

    5. Accept, reject, or modify hypothesis
      The results of an effective experiment will prove the hypothesis as either valid or not, providing a conclusion to build upon. Thus, the progressive nature of science.

      6. Another example: Penicillin: A fortuitous observation of contaminated bacteria cultures by French scientists early in this century led to the discovery of penicillin. They observed that there was a bacteria-free area between the contaminating mold and the bacteria. Alexander Fleming followed up on these observations, eventually leading up to the medicinal use of the antibiotic penicillin.