Scientific Inquiry: The Hypothetical-Deductive Approach

The Hypothetical-Deductive Method: Core Principles

The method of experimental science is called the hypothetical-deductive method. (From Greek 'meta-odos', meaning 'the way after' or 'pursuit of a path'.) The main element of this method is the hypothesis. A hypothesis is a general statement that establishes a causal relationship between two types of natural phenomena that are linked or associated. For example: "Whenever A appears, B will always follow."

This type of relationship establishes a universal and necessary causal connection. For example, "All bodies are attracted to the Earth with an acceleration of 9.8 m/s²" is a hypothesis.

Formulating Predictions

Once a hypothesis is formulated, we proceed to make a prediction. A prediction is a statement of fact that describes a particular outcome: under specified conditions, a certain event must occur as expected, because it logically follows from the hypothesis. For example: "If two identical balls are dropped from the same height, they will reach the ground at the same time."

Testing and Contrast: The Experimental Phase

Following the prediction, field observations or experimental tests are conducted to test the hypothesis. These tests can yield different results: if the prediction is true, the hypothesis is reinforced; if the prediction is not fulfilled, the hypothesis is significantly weakened.

This entire process, whether observational or experimental, is called the hypothesis testing or contrast process. This process involves the following four key elements:

1. The hypothesis itself, which gives the method its name.

2. The prediction that logically follows from the hypothesis.

3. The conditions that precede the verification of the hypothesis.

4. Auxiliary assumptions: general assumptions, distinct from the main hypothesis, which may be conscious or unconscious and can influence the outcome of the prediction.

Hypothesis Justification and Falsification

Once the hypothesis testing process is complete, and based on its outcome (favorable or unfavorable), we proceed to a new, argumentative phase called the hypothesis justification process. Some authors argue that a favorable outcome can support the hypothesis, but it is understood that no hypothesis is ever definitively established, and its "truth" is always provisional. However, an unfavorable outcome may force us to definitively abandon the hypothesis (a process known as falsification or refutation), especially if we carefully review all elements, particularly the auxiliary assumptions.