Scientific evidence is evidence which serves to either support or counter a scientific theory or hypothesis Fact: date=October 2007. Such evidence is expected to be empirical and properly documented in accordance with scientific method such as is applicable to the particular field of inquiry Fact: date=October 2007. Standards for evidence may vary according to whether the field of inquiry is among the natural sciences or social sciences Fact: date=October 2007.

Principles of inference

Evidence is information, such as facts, coupled with principles of inference (beliefs and assumptions), that make information relevant to the support or disproof of a hypothesis Fact: date=October 2007. Scientific evidence is evidence where the dependence of the evidence on principles of inference is not conceded, enabling others to examine the background beliefs or assumptions employed to determine if facts are relevant to the proof or disproof of a purported hypothesis .

A person's assumptions or beliefs about the relationship between alleged facts and a hypothesis will determine if that person takes the facts as evidence. Consider, for example alternative uses of the observation that day and night alternate at a steady rate. In an environment where the observer makes a causal connection between exposure to the sun and day, the observer may take the observation of day and night as evidence for a theory of cosmology. Without an assumption or belief that a causal connection exists between exposure to the sun and the observance of day, the observation of day will be discounted as evidence of a cosmological theory.

A person's assumptions or beliefs about the relationship between alleged facts and a hypothesis will also determine how a person utilizes the facts as evidence. Continuing with the same example, in an environment where geocentric cosmology is prevalent, the observation of day and night may be taken as evidence that the sun moves about the earth. Alternatively, in an environment where heliocentric cosmology is prevalent, the same observation may be taken as evidence that the earth is spinning about an axis. In summary, beliefs or assumptions about causal relationships are utilized to determine whether facts are evidence of a hypothesis.

Background beliefs differ. As a result, where observers operate under different paradigms, rational observers may find different meaning in scientific evidence from the same event. For example, Priestly, working with phlogiston theory, took his observations about the decomposition of what we know today as mercuric oxide as evidence of the phlogiston. In contrast, Lavoisier, developing the theory of elements, took the same facts as evidence for oxygen. Note that a causal relationship between the facts and hypothesis does not exist to cause the facts to be taken as evidence, but rather the causal relationship is provided by the person seeking to establish facts as evidence.