hypthèse

Hypothesis (French: hypothèse) is a tentative explanation or educated guess about a phenomenon that can be tested through observation and experimentation. The form "hypthèse" is a common misspelling. A hypothesis should be clear, specific, and testable, providing a statement about expected relationships between variables.

In scientific practice, a hypothesis proposes a relation between variables and serves as the basis for empirical testing. It must be falsifiable, meaning that there should be a possible outcome that could show the hypothesis to be false. Hypotheses are often refined during research as new data emerge and methods improve.

Common types include the null hypothesis (H0) and the alternative hypothesis (H1). The null hypothesis states that there is no effect or relationship, while the alternative predicts some effect or association. Hypotheses can be directional (one-tailed), suggesting a specific direction of the effect, or non-directional (two-tailed), indicating only that an effect exists. In statistics, hypotheses guide the choice of tests and the interpretation of results, including p-values and significance levels.

Formulating a hypothesis involves identifying the independent variable (the factor manipulated) and the dependent variable (the outcome measured), and often operationalizing these concepts so they can be observed and quantified. A hypothesis is a starting point for inquiry, not a final conclusion. It can be supported, refuted, or revised by evidence, and it helps distinguish theory-driven research from mere speculation.