Sense observation

Empirical evidence, also known as sensory experience, is the knowledge received by means of the senses, particularly by observation and experimentation. The term comes from the Greek word for experience, ἐμπειρία (empeiría).

After Immanuel Kant, in philosophy, it is common to call the knowledge gained a posteriori knowledge (in contrast to a priori knowledge).

Empirical evidence is information that justifies the truth or falsity of a claim. In the empiricist view, one can claim to have knowledge only when based on empirical evidence. This stands in contrast to the rationalist view under which reason or reflection alone is considered evidence for the truth or falsity of some propositions. Empirical evidence is information acquired by observation or experimentation. This data is recorded and analyzed by scientists. This is the primary source of empirical evidence. Secondary sources describe, discuss, interpret, comment upon, analyze, evaluate, summarize, and process primary sources. Secondary source materials can be articles in newspapers or popular magazines, book or movie reviews, or articles found in scholarly journals that discuss or evaluate someone else's original research.

Empirical evidence may be synonymous with the outcome of an experiment. In this regard, an empirical result is a unified confirmation. In this context, the term semi-empirical is used for qualifying theoretical methods that use, in part, basic axioms or postulated scientific laws and experimental results. Such methods are opposed to theoretical ab initio methods, which are purely deductive and based on first principles.

In science, empirical evidence is required for a hypothesis to gain acceptance in the scientific community. Normally, this validation is achieved by the scientific method of forming a hypothesis, experimental design, peer review, reproduction of results, conference presentation, and journal publication. This requires rigorous communication of hypothesis (usually expressed in mathematics), experimental constraints and controls (expressed necessarily in terms of standard experimental apparatus), and a common understanding of measurement.

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