In order to test whether the theory has the capability to describe, explain, and especially to predict, the behaviour of the real world, it is necessary to construct tests of the inferences arising from a theory. The outcomes of hypothesis testing provide feedback to the theory. If the hypotheses are not confirmed, then evidence exists that the theory may be wrong, and if it can be reproduced by others, then at least some aspects of the theory should be regarded as refuted. If the data support the hypotheses, then there is justification for increased or sustained confidence in the theory's effectiveness, or at least continued use of the theory. As findings accumulate which support a wide range of hypotheses generated from the theory, it tends to be regarded as authoritative within some range of applicability.
Empirical research is that which is based on observations of the real world.
It is important to appreciate the role of theory. It is perfectly feasible to create hypotheses directly from a small collection of observations, without any statement of underlying principles and logical derivation of inferences. On the other hand, where the hypotheses are derived from a body of theory, the results arising from the research accumulate, and can be used again by the researcher and others to flesh out knowledge. In summary, 'normal science' consists of extracting new hypotheses from an existing theory, testing them, and adding the results to the pool of knowledge. But Information Systems is an applied discipline, and lacks a solid body of existing theory.